Measuring technology in the food industry

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Measuring technology in the food industry Powered By Docstoc
					                              Incorporation into the
Measuring technology in the   recording of readings
                                  as part of the
food industry                    HACCP concept

                                               °C




                                               pH




                                              % RH




                                              % TPM




                                3rd revised
                                  edition
                                                                                                         Foreword



     FOREWORD
     This field guide, “Temperature Measurement in the Food Sector” has
     been produced in response to requests from many of our customers for
     practical instructions. It is intended primarily for those in positions of
     responsibility in the areas of food production, retail, catering, small
     businesses or logistics companies.
     The acquisition and use of measuring instruments often come up against
     reservations in practice. To overcome this problem, we have compiled
     some valuable instructions for you on how probes, sensors and meas-
     uring instruments can be effectively used. Examples of use are also
     provided to help get the most out of the instruments. Tips on the selec-
     tion and use of probes and sensors to avoid measuring errors are a key
     component of the technical information.
     Rational use in situ using simple tools can also give you peace of mind
     and be regarded as actively fulfilling the legal duty of care. That makes
     temperature measurements an indispensable part of your quality assur-
     ance.



     The Board of Directors




     Burkart Knospe                  Lothar Walleser




All due care is taken and specialist knowledge applied in compiling, preparing and publishing the
information supplied by our company. However, the information is provided with no guarantee in
respect of its application and use, including with regard to scientific or technical progress or the
updating of current legal regulations. It is prohibited to duplicate the information contained in this
booklet or to use it for other than the intended purpose without the prior consent of the author.



                                                                                                                    3
    Contents                                                                                                                                                                                                                            Contents

    1     In the interest of world health ........................................................................6             5 The HACCP concept ....................................................................................39
    1.1   Standard European food law ............................................................................7              5.1 Application in the retail food industry ..............................................................40
    1.2   The seven principles of the HACCP concept ....................................................8
    1.3   Obligations for food business operators ............................................................9                 6   Technical background information ..............................................................44
    1.4   Requirements for thermometers and data loggers ..........................................11                           6.1 Temperature sensors (design/operation) ........................................................44
    1.5   Causes of food poisoning ..............................................................................11             6.2 Sensor, probe, measuring unit ........................................................................46
    1.6   Risk or hazard? ..............................................................................................12      6.3 Different designs of probes and their uses ......................................................47
    1.7   HACCP and ISO 9000 ....................................................................................12             6.4 Infrared measuring instruments/infrared probes ..............................................49
                                                                                                                                6.5 Measuring instruments with data memory, product assignment, printing function
    2     Little helpers or a health hazard: microorganisms ......................................14                                                                                                                                               53
    2.1   Dependence on temperature for multiplication of germs ..................................15                            6.6 Data loggers ..................................................................................................55
    2.2   Conditions for germ growth ............................................................................16
    2.3   Normal germ content of some foods ..............................................................17                    7     Tips for using the measuring instruments ..................................................57
    2.4   Foods in which dangerous germs multiply rapidly ............................................18                        7.1   Storing the measuring instrument ..................................................................57
    2.5   Specific hazards when processing food ..........................................................19                    7.2   Fluctuating ambient temperatures ..................................................................57
                                                                                                                                7.3   Penetration depth ..........................................................................................57
    3     Parameters in the food industry ..................................................................20                  7.4   Measuring time ..............................................................................................59
    3.1   Temperature ..................................................................................................21      7.5   Official calibration/calibration – who needs what? ............................................59
    3.2   pH value ........................................................................................................21   7.6   Documentation ..............................................................................................60
    3.3   Relative humidity ............................................................................................23
    3.4   Measurement of quality of cooking oil ..............................................................24                8     Tips for selecting measuring points ............................................................61
    3.5   Measuring in rooms ........................................................................................25         8.1   Chest freezers ................................................................................................61
    3.6   Probe designs and selecting probes ..............................................................26                   8.2   Cold rooms and store rooms ..........................................................................62
    3.7   Accuracy data ................................................................................................28      8.3   Serving food ..................................................................................................63
    3.8   Display unit ....................................................................................................29   8.4   User tips ........................................................................................................64

    4     Documents and records ..............................................................................31                9     Specimen protocols ....................................................................................71
    4.1   Documents in the Incoming Goods department ..............................................32
    4.2   Documents as part of self-assessment ............................................................35
    4.3   Check measurements on plant and equipment ................................................35
    4.4   Quality controll plan ........................................................................................36
    4.5   Dynnamic checking ......................................................................................38




4                                                                                                                                                                                                                                                            5
    World health                                                                                                                                                                                                                   World health

                   1         In the interest of world health
                                                                                                                                                                    WHO
                   Good quality, a low germ content and a good taste were actually always taken
                   for granted with regard to foodstuff; however, raw materials and finished foods
                                                                                                                                              World Health Organization
                   which are stored, transported and prepared are exposed to hazards. Reports of                                           Codex Alimentarius Committee, Rome
                                                                                                                                                           European Union
                   food poisoning incidents (e.g. E-coli bacteria poisoning of 900 school children in                                           Food and Drug Administration, USA
                   Japan in 1996) attract not only public interest, they also demonstrate the                                                Australian Food and Sanitary Administration
                   hazards in relation to the handling of food. At the United Nations, the World Health
                   Organization (WHO) has turned its attention to the subject of food safety and
                   health. 150 nations together making up 97% of the world population have




                                                                                                                      National guideline




                                                                                                                                                                    National guideline




                                                                                                                                                                                         National guideline
                                                                                                                                               National guideline




                                                                                                                                                                                                              National guideline
                                                                                                                       for each country
                   ratified this section of the world health programme. “From farm to fork”: this is the




                                                                                                                                                                     for each country




                                                                                                                                                                                          for each country
                                                                                                                                                for each country




                                                                                                                                                                                                               for each country
                   ambitious definition of quality assurance in a position paper by the WHO from
                   1992. The HACCP paper applicable to the whole of Europe, EU Directive
                   93/43/EU from 1993, was derived from this paper. This well known paper was
                   replaced in 2004 by a whole series of EU regulations which have also replaced
                   the so-called “vertical regulations”, such as the milk/eggs or mincemeat regula-
                   tions. In Europe, the so-called transition period expired on 01.01.2006; i.e. these
                   regulations are enforceable laws and are monitored as such.
                   The basis for these guidelines, the HACCP concept, was devised by an organi-
                                                                                                                                                        GOAL:
                   zation which is part of the WHO: the Codex Alimentarius Committee. This
                   committee gathers information, heads talks and agreements with representa-
                                                                                                                                            Battle against food poisoning.
                   tives and associations worldwide and communicates with producers, authorities                                                 Safer food products!
                   etc. Major economic associations such as the European Union, NAFTA, EFTA
                   are in constant contact with the Codex Committee so that results can be set
                   down as guidelines. The HACCP concept is now well known worldwide and is
                   applied in nearly all regions. HACCP stands for:
                       Hazard Analysis Critical Control Points                                             1.1       Standard European food law
                       Hazard analysis and critical control points                                         After a Europe-wide directive was set down by the European Union in 1993
                                                                                                           (Directive 93/43/EU), all European countries have national guidelines. In order to
                   The HACCP concept, which will be discussed in detail in this brochure, is de-           standardize these already high standards even further, the European Union
                   signed to prevent mistakes from happening. HACCP was developed for the                  resolved to take a further step: the standardization of European food law.
                   NASA space exploration project. The question in the sixties was how to ensure           93/43/EU was replaced by five regulations in 2004. Due to the fact that these are
                   that astronauts do not carry any bad foodstuffs that could cause a mission to fail?     regulations, they are immediately legally effective (after a transition period) in
                                                                                                           European countries and applicable to all trading partners of the EU without the
                                                                                                           individual country having to pass a separate national law.




6                                                                                                                                                                                                                                                 7
    World health                                                                                                                                                                                  World health

                   The new regulations of the EU food law:                                             Critical control points (CCPs)
                   EC 178/2002 = General principles and requirements of the food law. Basic docu-      Unlike critical points, significant hazards may arise if critical control points are not
                                 ment for further directives and regulations.                          duly observed. Or to put it another way, if these points are managed with target-
                   EC 852/2004 = Regulation of 29.04.2004 regarding food hygiene.                      ed measures, hazards can be avoided. Critical control points include:
                   EC 853/2004 = Specific regulation governing foods derived from animals.             • Heating steps
                   EC 854/2004 = Specific process regulations for official                             • Adequate cooling (if there is no further heating)
                                 monitoring of products derived from animals.                          • Screens
                   EC 882/2004 = Regulation regarding official inspections to verify compliance        • Magnets
                                 with laws pertaining to food and animal feed.                         • Metal detectors.

                   The cornerstone is EC 852/2004. The transition period expired on 01.01.2006;        1.3 Obligations for food business operators
                   these regulations have therefore been applicable law in the EU since this cut-off
                                                                                                       To whom does the new EU regulation apply?
                   date.
                                                                                                       The regulation applies across all production, processing and distribution stages
                                                                                                       for foods as well as to exports. If original production is also subject to certain re-
                   1.2       The seven principles of the HACCP concept                                 strictions, the regulation also affects those involved in production, transport, stor-
                   The HACCP concept is based on self-monitoring. The HACCP concept is to be           age and distribution (retailers, caterers, hotel industry etc.).
                   implemented effectively by means of a 7-point programme:                            The food business operator has a key role in the new regulations.
                   • Determination of the relevant hazards (hazard analysis)
                                                                                                       Who is a food business operator?
                   • Identification of critical control points
                                                                                                       A food business operator is anyone involved in activities relating to the produc-
                   • Definition of limit values (CCPs)
                                                                                                       tion, processing or sale of foods. It is irrelevant whether or not these companies
                   • Definition and implementation of efficient monitoring
                                                                                                       are set up to make a profit, or whether they are in the public or private sector.
                   • Specification of corrective measures
                   • Production of documents and records (documentation)
                                                                                                       The requirements placed on these “food business operators” by these regu-
                   • Designation of a regular verification process (self-monitoring obligation).
                                                                                                       lations are even greater than those under the previous directives. Apart from a
                                                                                                       functioning self-monitoring system, the key elements are documentation, train-
                   The HACCP concept draws a distinction between critical points and critical con-
                                                                                                       ing, traceability and compliance with the cooling chain.
                   trol points.
                                                                                                       Documentation
                   Critical points
                                                                                                       Food traders are obliged to do the following:
                   Critical points are those points in the process which, while they do not pose a
                                                                                                       a) prove to the relevant authorities that they are conforming to the requirements
                   health risk, can be regarded as critical actions; examples include:
                                                                                                       of the regulation [...];
                   • Quality parameters                                                                b) ensure that the documents from which the processes are developed as set out
                   • Units of product specifications                                                   in this article are up-to-date at all times;
                   • Product marking (labels, best before date etc.)                                   c) store all remaining documents and records for an appropriate period of time.
                   • Compliance with legal specifications
                   • Pest control




8                                                                                                                                                                                                                9
     World health                                                                                                                                                                               World health

                    Training                                                                               1.4       Requirements for thermometers and data loggers
                    Food traders must ensure the following:
                                                                                                           In addition to the directives and regulations for food business operators, there
                    1. company employees handling foods are monitored according to the nature of           are now also specifications for the manufacturers of thermometers which deal
                    their work and are instructed and/or trained in food hygiene;                          with the technical properties and minimum requirements for thermometers and
                    2. those people responsible for the development and application of this regula-        data loggers. This was necessary in order to arrive at a standard rule regarding
                    tion or for the implementation of pertinent guidelines are given appropriate train-    discrepancies in measurements, the period of time over which temperatures are
                    ing in all areas of applying the HACCP principle, and                                  recorded,
                    3. compliance with all requirements of national laws regarding training                protection against dirt and water etc. EU regulation 37/2005 entitled “Monitor-
                    programmes for employees in certain food sectors.                                      ing of temperatures in the means of transport, warehousing and storage of quick-
                                                                                                           frozen foodstuffs intended for human consumption” defines three further EU
                    Traceability                                                                           regulations which give details:
                    The directive prescribes records in both directions here (extract from the text of
                                                                                                           • EN 12830 Requirements for data loggers
                    the law):
                                                                                                           • EN 13485 Requirements for hand-held measuring instruments
                    “Food and animal feed traders must be able to identify each and every person
                                                                                                           • EN 13486 Defines requirements and methods for calibrating data loggers
                    from whom they have received a foodstuff [...], an animal from which food is to
                                                                                                                      and hand-held measuring instruments in the calibration laboratory
                    be extracted or a substance [...].
                    To this end, they shall set up systems and processes whereby they can submit
                                                                                                           Users should ensure that the instruments to be procured
                    this information to the relevant authorities on request (documentation).
                                                                                                           comply with these standards and that an appropriate
                    Food and animal feed traders shall also put in place systems and processes to
                                                                                                           type test (approval) has been performed by the manu-
                    identify other companies to whom their produce has been delivered. This infor-
                                                                                                           facturer.
                    mation shall be made available to the relevant authorities on request.”
                                                                                                           1.5       Causes of food poisoning
                    Compliance with the cooling chain
                    In the case of foods which cannot be stored at room temperature without po-            What’s it all for? That’s what many quality controllers, production managers or
                    tential problems, the cooling chain must not be interrupted.                           head chefs may wonder. And in view of the not inconsiderable investment a
                    • Any deviations (e.g. during loading and unloading) are only permitted within         HACCP concept requires, they may indeed be justified in asking the question.
                       limits (maximum 3 °C) and for a short period of time.                               But let us look at how a “foodstuff” was produced in the past and today. Eighty
                    • In means of transport (e.g. containers, trailers, cargo holds of trucks) with more   to a hundred years ago, production was local; for instance, hens’ eggs were
                       than 2 m², or storage facilities with more than 10 m³, the temperature must be      “produced” on the farm and distributed locally (corner shop, local market, direct
                       recorded.                                                                           sales). If food poisoning broke out, only a relatively small number of people were
                    • The thermometers used must be calibrated at regular intervals.                       affected. The problem was a local one.

                                                                                                           The same situation today: globally operating groups produce, distribute and sell
                                                                                                           food. Our farmyard of then may be a battery farm with 60,000 hens today. The
                                                                                                           eggs are distributed to food producers (to make pasta, cakes and pastries, con-
                                                                                                           fectionary etc.) nationwide or abroad. The thousands of foodstuffs produced in
                                                                                                           this way are distributed to the consumer via food shops, supermarkets etc.
                                                                                                           Several hundred thousand people may be affected.




10                                                                                                                                                                                                             11
     World health                                                                                                                                                                           World health

                    Causes of food poisoning?                                                              be calibrated at regular intervals. Because HACCP and ISO 9000 are not mutu-
                                                                                                           ally exclusive but on the contrary complement each other perfectly, a combined
                    –   Fast food, too many “producers”
                                                                                                           concept is implemented in the USA. This is called HACCP 9000.
                    –   Diverse range of foods
                    –   Convenience products (semi-cooked products)
                    –   Factory farming (e.g. salmonella)
                    –   Mass tourism (unhygienic work, lack of time)
                    –   Globalization (raw products as components of food
                        in other countries).

                    Questions on the food risk (partly from the Codex Alimentarius text)
                    – Does the product contain sensitive ingredients?
                    – Is it destined for sensitive target groups
                      (old people, the sick, infants etc.)?
                    – Is there a step in the process which kills off risk substances?
                    – Are there potentially toxic basic substances present in the food
                      (fungi, spores, proteins etc.)?

                    1.6        Risk or hazard?
                    A distinction is made between risk analysis and hazard analysis:
                    Risk analysis = is there a risk? Where?
                    Hazard analysis = when does the risk become a hazard?

                    In principle, the storage, production and serving of food and foodstuffs always
                    involves a risk due to bacteriological contamination. This risk only becomes a
                    hazard, however, when a certain volume of germs is reached. The hazard only
                    starts when the human body is “overburdened” and can no longer cope with the
                    invaders. However, this also means that just a few spores, germs etc. which get
                    in during production can multiply if the food is not properly treated, to the point
                    where they suddenly become a hazard. The answer is to introduce steps in the
                    process of food production to avoid this hazard (e.g. killing off bacteria by heat).

                    1.7        HACCP and ISO 9000
                    ISO 9000 (EN 29000) is a quality assurance standard which originated in
                    industry. A company working to ISO 9000 defines processes, monitors the
                    result, makes changes if things go wrong and documents the results. HACCP
                    and ISO 9000 are very similar in this respect. A core feature of ISO 9000 is cali-
                    brating measuring and test equipment at regular intervals. Since temperature is
                    one of the critical control points in HACCP, the thermometers used should also


12                                                                                                                                                                                                         13
     Helpers or health hazard?                                                                                                                                                    Helpers or health hazard?

                         2.         Little helpers or a health hazard:                                      2.1            Dependence of germs on temperature for
                                    microorganisms                                                                         multiplication
                                                                                                            Microorganisms can only multiply within a specific temperature range. Above or
                         Bacteria, fungi and microorganisms in general are useful helpers on the one hand   below that range, multiplication cannot take place. At cool temperatures (< 7 °C),
                         (for instance yeast used in bread making, bacteria which make sour milk, acetic    bacterial growth slows down. Division occurs at considerably longer intervals. At
                         acid bacteria which produce alcohol by fermentation etc.). On the other hand,      very cold temperatures (< -18 °C), the microorganisms can no longer divide.
                         they can cause diseases (salmonella, E-coli, hyphomycetes etc.). The bacteria      Bacterial growth comes to a halt. But this does not mean that the germs are dead;
                         do so by using the same “food source” as human beings: our foodstuffs. In bio-     they are simply “sleeping”.
                         logical terms, decomposition of food serves to break down the substances and
                         return the nutrients to the natural cycle. That makes it important for humans to   At temperatures above 40 °C, bacterial growth is also restricted. At temperatures
                         eat the foodstuff at the “right time”. Food that has gone bad for a human is a     above 65 °C – 70 °C, certain kinds of germ start to die. Above 125 °C,
                         nutrient for plants.                                                               microorganisms have no further chance of survival. This is therefore the
                         Bacteria multiply by dividing. In favourable conditions (depending on moisture     temperature range used for sterilizing (making things germfree).
                         and temperature) this can occur every 20 minutes So 100 bacteria at time 0
                         become 200 after 20 minutes, 400 after 40 minutes, 800 after 1 hour, 1600 after
                         1 hour 20 minutes, and so on.


                                                                            3,276,800 germs
                                                                               in 5 hours

                                                                                                                                                    Destruction of all bacteria




                                                                                                                                                    Most of the bacteria begin to be destroyed
                                                                                                                                                    Bacterial growth slows down




                                                                                                               Dangerous
                                                                                                                                                    Optimum temperature for




                                                                                                                 zone
                                                            409,600 germs                                                                           bacterial growth
                                                              in 4 hours

                                                                                                                                                    Bacterial growth accelerates
                                                                                                                                                    Ideal refrigerator temperature

                                            51,200 germs                                                                                            End of bacterial multiplication
                                              in 3 hours
                              6,400 germs                                                                                                           Ideal freezer temperature
            800 germs          in 2 hours
             in 1 hour




14                                                                                                                                                                                                            15
     Helpers or health hazard?                                                                                                                                                                       Helpers or health hazard?

                   2.2         Conditions for germ growth                                                        2.3          Normal germ content of some foods (examples)
                   Besides temperature, the acidity, water content, nutrient content and structure               A single germ or microorganism is hardly noticed. A few hundred to a few thou-
                   of the foodstuff also play an important part in multiplication. One or more                   sand microorganisms are not harmful. Only when they multiply excessively
                   parameters from the list below can be used to make foodstuffs keep longer.                    (depending on the microorganism) does the consumer “realize” they are present.
                                                                                                                 Here are few examples of typical germ contents in foodstuffs and consumer
                                                                                                                 goods:
                                   Strong growth           Poor growth            Measures/
                                   (undesirable)           (desirable)            preservation
                                                                                                                 Total number per 10 square centimetres:
                                                                                                                 Lettuce (unwashed)........................................10,000–1,000,000
                   Temperature     > +7 °C … < +65 °C      < +7 °C                Refrigeration                  Lettuce (washed) ................................................1,000–100,000
                   conditions                              < -18 °C               Deep freezing                  Fresh strawberries ..........................................1,000–1,000,000
                                                           > +65…+70 °C           Heating
                                                                                                                 Pork (fresh) ....................................................................100,000
                                                           > +120 °C              Sterilizing
                                                                                                                 Pork (hung) ............................................................100,000,000
                   Acidity         > 4.2 pH                < 4.2 pH               Natural fruitacids             Weighing scales (butcher’s) ........................................750–4,000
                                                                                  Addition of acid
                                                                                                                 Kitchen table ........................................................................300
                                                                                  (e. g. salad dressings)
                                                                                                                 Kitchen cutlery (clean) ....................................................10–250
                   Water content > 15 %                    < 15 %                 Drying                         Palm of hand
                                                                                  (meat, bread etc.)
                                                                                                                 (washed thoroughly)........................................................10–250
                                                                                  Addition of sugar (jam)
                                                                                  Salting                        Total number per gram or millilitre:
                                                                                  (meat, fish etc.)              Steak tartar (with egg and seasoning) ........100,000–30,000,000
                   Nutrient content High protein/          Low protein/           Sparing use                    Liver sausage (on bread roll) ..........................................500,000
                                    carbohydrate content   carbohydrate content   of e. g. meat ingredients,     Italian salad (home-made) ..........................................3,000,000
                                                                                  eggs etc.                      Onions (chopped) ............................................................20,000
                   Structure       Small pieces,           Large pieces,          Leave protective packaging     Pepper (ground) ............................................30,000–1,000,000
                                   unprotected             natural protection,    on until processing,           Milk (pasteurized) ........................................................to 10,000
                                                           e. g. eggshell,        do not cut into small pieces   Source: BERG, THIEL and FRANK, “Rückstände und Verunreinigungen in Lebensmitteln” (Residues and
                                                           connective tissue                                     Contaminants in Foodstuffs),
                                                                                                                 UTB 675, Steinkopff-Verlag, Darmstadt, 1987

                   These are exactly the steps followed in natural processing, which we have been
                   doing for centuries. To make jam, we use the natural fruit acids in the fruit in con-
                   junction with the process of “dehydration” by adding plenty of sugar. Dried meat
                   (dry-cured beef, Parma ham etc.) is salted on the one hand and air-dried on the
                   other to reduce the water content. Meat in large pieces (joints, not divided up) are
                   often protected by connective tissue to make the surface that germs can attack
                   smaller. Minced meat, on the other hand, is chopped up so small that bacteria
                   have a huge area to attack. For that reason, minced meat should be consumed
                   on the same day it is minced. It is extremely important to keep meat products
                   cool.




16                                                                                                                                                                                                                               17
     Helpers or health hazard?                                                                                                                                        Helpers or health hazard?

                   2.4        Foods in which dangerous germs multiply rapidly                           2.5       Specific hazards when processing food
                   Food                             Reasons                                             1. Insufficient attention is paid to personal hygiene of employees
                                                                                                        2. “Clean” and “unclean” processes are not separated strictly enough
                   Minced meat                      • High nutrient content                             3. Raw and heated foods are stored together
                                                    • Distribution of microorganisms                    4. Food is insufficiently refrigerated or heated
                                                      throughout the food due to
                                                                                                        5. Cooked food is stored for too long without refrigeration
                                                      mincing
                                                                                                        6. Refrigeration systems are overloaded. Result: temperatures are too high
                   Poultry, game                    • Origin and processing                             7. Thawing liquid comes into contact with other food
                   Certain meat products            • Composition
                   (sausages, cold cuts)            • Poor hygiene during production                    As can be seen from the list, the temperature plays a key role in the processing
                   Lightly roasted or               • Not all the germs are killed during roasting or   and storage of food.
                   cooked meat                        cooking
                                                    • Poor hygiene during processing                    The following findings emerged from a study of a Belgian restaurant chain:
                   Raw crustaceans, shellfish       • Origin in polluted water                          Reasons food goes off in restaurants
                   and molluscs                     • Poor hygiene during processing                    • Incorrect refrigeration            56%
                   Egg and milk dishes, ice cream   • High germ content in the ingredients              • Products more than 12 hours old 19%
                                                    • Insufficient heating during production            • Insufficient reheating             20%
                   Mayonnaises and salads           • Composition                                       • Other reasons                      5%
                                                    • Poor hygiene during production
                                                    • Insufficient heating




18                                                                                                                                                                                                19
     Parameters in the food industry                                                                                                                                   Parameters in the food industry

                   3.        Parameters in the food industry                                                3.1        Temperature
                                                                                                            After time, temperature is the physical variable most often measured. Different
                   The four most important parameters for food monitoring are time, temperature,            types of thermometer are used. Digital thermometers have established them-
                   pH value and relative humidity. In the case of almost all products, time is indi-        selves in professional use. These are highly accurate and robust in everyday use.
                   cated by the Best Before Date (BBD) and in some cases by the Use By Date.                The thermometer consists of two components: the display unit and the probe.
                   Goods sold loose do not carry a date; the length of time they can be kept                The probe houses the sensor, the electronic component that converts the
                   depends on their condition.                                                              physical reading into an electrical signal. The probe itself is made of appropriate
                   The best before date is principally relevant to warehousing and stock turnover.          material and suitably shaped for the particular area of use. The sensor is attached
                   Computer-assisted stock control and regular inventory-taking coupled with                to the measuring instrument. The measuring instrument converts the electrical
                   correct stock rotation (first in, first out principle) ensure products that will keep    signals from the sensor into a reading that can be read off.
                   well are available in the different departments. Special equipment to monitor
                   product life is needed in only a few cases.
                   Temperature, on the other hand, is the most important parameter. Frozen food
                   and cold shelves are already covered by legal requirements or limit values. But
                   even the storage instructions that appear on many packs “Store in a cool, dry
                   place” sometimes have to be monitored. Temperature is still responsible for many
                   instances of food going off and impaired quality, and correct storage of foodstuffs
                   for long periods is therefore obviously essential.
                   The pH value is used for quality assessment in the food industry. It particularly
                   affects the properties of meat and meat-based products, in particular the water
                   binding capacity, taste, colour, tenderness and shelf life. In the bakery sector, the
                   acidity of the leaven can be determined by means of the pH value. In the case of
                   products such as salad dressings, the pH value helps to ensure a constant qual-
                   ity or a constant acidity in the product.
                   Relative humidity is rarely indicated in exact terms and often is not given the                             Figure 1: testo 110 with stainless steel probe
                   importance it deserves. The abovementioned storage instructions do not give a
                   value to be adhered to. This is where specialist knowledge on the part of the
                                                                                                            3.2        pH value
                   distributor comes into play in determining the conditions to be fulfilled as far as is
                   technically feasible and depending on the packaging used.                                The acidity of certain fruits, salad sauces, jams or similar is a natural barrier to the
                   Deep frying is becoming increasingly popular. However, the properties of the             growth of germs. The lower the pH value, the harder it is for germs to multiply. In
                   cooking oil used alter during the deep frying process due to heat, oxygen and the        dough products such as leaven, the pH value is an indicator of the quality and
                   effect of water: the oil ages. While it used to only be possible to obtain informa-      condition of the cooking dough. However, the pH value is most important when
                   tion about the quality of cooking oil through elaborate chemical tests or relative-      it comes to processing meat and sausages. As already mentioned, the pH value
                   ly imprecise chemical measuring strips, it is now possible to get this information       has a crucial effect on the key product properties such as the water binding
                   electronically. This process is so easy to manage that it can also be carried out        capacity, taste, colour, tenderness and shelf life of the meat. The pH range of
                   by non-specialists A suitable sensor is kept in the cooking oil and the value is read    interest here is between 4.5 and around 8.
                   from a display. The parameter % TPM (total polar materials) is the reference             With raw meat, as well as normal meat a distinction is made between what is
                   value used in many countries and is also measured by national food laboratories.         referred to as DFD (dark, firm, dry) and PSE (pale, soft, exudative) meat.




20                                                                                                                                                                                                       21
     Parameters in the food industry                                                                                                                                   Parameters in the food industry

                                                                                                                Examples of maturing times for meats:
                                                                                                                Pork               2 – 5 days       Beef products
                                                                                                                Poultry            2 – 5 days       Cooked meat              4–6 days
                                                                                                                Veal               2 – 3 days       Joints                   10-14 days
                                                                                                                Lamb               4 – 5 days       Steak and roast beef     3–4 weeks
                       pH value




                                               Normal
                                               DFD
                                                PSE                                                             The pH value is also important for sausage production. In the case of raw
                                                                                                                sausage, e.g. salami, Mettwurst or Landjäger which are not heat-treated,
                                                                                                                maturing takes place by means of microbial processes. The pH value is an
                                             Living                  pH 1 after 1 h         pH 2 after 24 h     indicator of what stage of maturity the meat has reached.

                                                      Figure 2: pH profile of meat within                       3.3       Relative humidity
                                                       the first 24 hours after slaughter                       Atmospheric humidity is particularly important in connection with the storage of
                   DFD meat, which is dark, firm and dry, starts with a pH value of just over 7 and             dry goods for prolonged periods of time. If substances that are sensitive to
                   falls towards 6.5 over a 24-hour period. PSE meat (pale, soft, exudative) on the             moisture are left not fully protected in rooms
                   other hand falls from around 7 to below 5.5 and then climbs again towards 5.6 -              for a long time, moisture may be
                   5.7. This happens within the first 24 hours of slaughtering and is an indicator of           absorbed. Microbiological decomposition
                   the available options for further processing.                                                such as mould depends very much on the
                                                                                                                moisture present and is particularly likely to
                   The maturity of meat can also be determined by means of the pH value. The meat               occur with condensation following big tem-
                   of freshly slaughtered or slain animals is barely edible. It is tough and flavourless        perature fluctuations. Ensuring correct stor-
                   immediately after slaughter and only acquires its tenderness and taste once it               age conditions is therefore very important.
                   has matured.                                                                                 Moisture       in   the      atmosphere       is
                                                                                                                described in terms of “relative humidity”. This
                                                                                                                is a percentage figure which shows how
                                                                                                                much of the maximum possible quantity of
                                                                                                                water vapour is present in the air at any given
                                                                                                                moment. Because this percentage depends
                                                                                                                on temperature, the temperature has to be
                                                                                                                stated at the same time. Probes used to
                                                                                                                measure relative humidity therefore have to
                                                                                                                be fitted with an additional temperature probe Figure 5: Determining air humid-
                                                                                                                to record ambient temperature. Because ity when storing food
                                                                                                                relative humidity sensors are highly sensitive, they are housed in specially shaped
                                                                                                                probe shafts which allow air to circulate freely while protecting the sensor.
                                  Figure 3: pH measurement                 Figure 4: Determining the pH value
                                     when filleting up meat                    as sausages are maturing



22                                                                                                                                                                                                       23
     Parameters in the food industry                                                                                                                                       Parameters in the food industry

                   3.4        Measurement of quality of cooking oil                                           and 27% TPM. In some countries, the quality of cooking oil is already checked
                                                                                                              as part of the food inspection. Fines will be incurred if the limit values are
                   Deep fat frying consists of cooking products in hot oil. This quick and simple
                                                                                                              exceeded.
                   method of preparing tasty products is becoming increasingly popular. However,
                                                                                                              Another positive aspect of measuring TPM is the possibility that this offers of
                   the quality of the oil changes more quickly or slowly depending on the product
                                                                                                              adjusting the fat to the optimum range for the cooking oil. This is particularly
                   being deep fried. After a certain period of deep fat frying, every cooking oil is
                                                                                                              advantageous in the industrial sector. With huge industrial deep fat fryers, a
                                                                            spent. Various degrada-
                                                                                                              certain amount of oil automatically escapes through the product. It is therefore
                                                                            tion substances are pro-
                                                                                                              rare that all of the oil is replaced; it is topped up. If the polar materials value is kept
                                                                            duced in the fat as a result
                                                                                                              constant (e.g. 16 – 20% TPM), the result is an even browning and product
                                                                            of deep fat frying. They are
                                                                                                              quality throughout the whole production period.
                                                                            referred to under the col-
                                                                            lective term “total polar
                                                                                                              3.5        Measuring in rooms
                                                                            materials” (abbreviated to
                                                                            % TPM). Total polar mate-         Measurements taken inside a room may be distorted by what is known as
                                                                            rials is a generic term for the   stratification around surfaces.
                                                                            free fatty acids, mono-           The risk of stratification arises if the surface temperature differs a great deal from
                                                                            glycerides and diglyc-            the air temperature. As already explained, relative humidity depends very much
                                                                            erides and a number of            on temperature, and may therefore also be affected. To avoid measuring errors
                                                                            other oxidation products.         of this kind, a minimum distance from surfaces should be observed. This mini-
                        Figure 6: Checking cooking oil in gastronomy
                                                                            They affect not only the          mum distance has been reached when al-
                   consistency, taste and appearance of the fat, but also its deep frying quality. A          tering the distance produces no further
                   product which is deep fried in spent oil very quickly forms a dark crust but at the        changes in the temperature and relative                  70% RH

                                                                                                              humidity readings. The location for every                                 Troom = 15 °C
                   same time sucks in a large quantity of fat. In fat with a high proportion of polar
                   materials, the water can escape more quickly via the fat and the product dries             measurement should therefore be chosen
                   out more quickly.                                                                          with care and an appropriate measuring
                   Examinations have shown that decomposed fat can cause severe stomach ache                  distance observed. This also applies to the
                                                                                                                                                                                             50% RH
                   and digestive complaints, among other things. Nearly all food laws prohibit the            intake of conditioned air from heating or re-
                                                                                                                                                                       Tsurface = 15 °C
                                                                            sale of any foods not fit for     frigerating equipment. Stratification can
                                                                            consumption. This in-             occur in this way in static air between the
                                                                            cludes any foods in a con-        floor and ceiling, in big store rooms for ex-
                                                                            dition unacceptable to            ample. Check measurements should
                                                                            consumers.                        therefore be taken at the points which have Figure 8: A minimum distance
                                                                            Thanks to the possibility of      been found to be representative from a must be observed when measur-
                                                                            measuring this parameter          survey of room air conditions. Permanent ing temperature and relative
                                                                            quickly and easily with           probes at various locations are usual in humidity.
                                                                            electronic instruments,           cold rooms.
                                                                            food processors and
                                                                            cooks are able to deter-
                                                                            mine the quality of their
                                                                            cooking oil themselves.
                           Figure 7: Optimum cooking oil in the             Typical values for spent oil
                             food industry through measuring                are between 24% TPM
24                                                                                                                                                                                                           25
     Parameters in the food industry                                                                                                                                    Parameters in the food industry

                   3.6       Probe designs and selecting probes                                             industry is to check the temperature, i.e. to compare a known or required nomi-
                                                                                                            nal value with the actual value. To this end, a probe must be placed in atmos-
                   Temperature probes measure the temperature of the medium in which they are
                                                                                                            pheric air, in liquids and between packagings or solid products. A penetration
                   being kept and forward this temperature to the sensor. For this to happen, the
                                                                                                            probe serves these purposes.
                   material must adapt to the outside temperature. The probe requires a certain
                                                                                                            Special designs of probe which can penetrate the frozen product are required to
                   period of time to settle to the substance being measured. A probe has recog-
                                                                                                            measure temperatures on special products, such as frozen foods.
                   nized the temperature of the substance being measured when its temperature is
                                                                                                            The purpose of humidity probes on mobile units is to be able to take current
                   99% identical to the outside temperature. This period is known as the t99
                                                                                                            measurements at any given time. These probes do not vary in design. In corro-
                   period. The actual measuring process is complete once the display on the meas-
                                                                                                            sive media, the sensor should be protected by a sintered cap.
                   uring instrument no longer shows any significant change. The equalization of the
                   reading displayed to the outside temperature is shown in Figure 9. The t99
                   period is important when it comes to daily use in a range of locations, as is the
                   case in the retail food industry. The sequence of measurement for this may be
                   freezer temperature, ambient temperature and the temperature on delivery from
                   the refrigerated van. The shorter the t99 period, the quicker the probe reacts to
                   different temperatures and the less standstill times occur.                                         Immersion probe Penetration probe    Air probe     Surface probes

                                                                                                                   Figure 10: Different designs of probe for measuring temperature


                                                                                                            A probe should ensure complete contact with the medium. This is the only way
                                                                                                            that the temperature will settle quickly. The tip of a penetration or immersion
                                                                                                            probe must be placed in the medium to a certain depth, according to its diame-
                                                                                                            ter. This minimum depth depends on the diameter of the probe shaft.

                                                                                                            Note:    Insert/immerse probe tip at least 5 x shaft diameter.
                                                                                                            Example: Probe tip          = 4 mm diameter
                                      Figure 9: Response of temperature probes                                       Penetration depth = 4 mm x 5 = 20 mm

                   Humidity probes usually have a capacitive humidity sensor, a capacitor whose
                   capacitance varies according to the ambient humidity. This electrical value is
                   expressed as relative humidity and shown on the display. The humidity sensors
                   also require a certain equalization period. In addition, the medium being meas-
                   ured, the air, must flow evenly around the sensor so that a representative result
                   is obtained. When taking measurements in fast air streams (air conditioning                                      ø
                   systems, refrigerating systems) or in polluted air, the sensor must be protected
                   by a cap that is permeable to air. Special sintered caps let the air get freely to the                                          ‡5 x ø
                   sensor and also prevent damage.

                   There are special probes for every application. A universal probe with as broad
                   a range of applications as possible is ideal for checking temperatures with a
                   hand-held instrument. The purpose of measuring temperatures in the retail food
                                                                                                                       Figure 11: Penetration depth for temperature measurements
26                                                                                                                                                                                                        27
     Parameters in the food industry                                                                                                                              Parameters in the food industry

                   Inserting the probe deeper or pushing it in fully between packagings does not         Accuracy          Reading at               Reading at             Reading at
                   affect the measurement; the temperature at the tip of the probe is always meas-       data              -18 °C                   +25 °C                 +100 °C
                   ured.                                                                                 ±0.2 °C          -17.8…-18.2 °C            24.8…25.2 °C           99.8…100.2 °C
                   Humidity probes respond particularly sensitively, even to small changes in rela-      ±0.2% of reading -17.96…-18.04 °C          24.95…25.05 °C         99.8…100.2 °C
                   tive humidity. You can see this if you exhale next to the sensor. A stable reading
                                                                                                         ±0.2 °C and
                   is not obtained. You should therefore direct the relative humidity probe as far
                                                                                                         ±0.2% of reading -17.76…-18.24 °C          24.75…25.25 °C         99.6…100.4 °C
                   away from your body as possible and do not breathe in the direction of the meas-
                   urement. Measurements taken in extremely confined spaces, such as on a shelf
                                                                                                                      Table 1: Accuracy of probes at different temperatures
                   between closely spaced packagings are only rarely representative, as the mois-
                   ture content equilibrium between the atmosphere and the packaging is strong
                                                                                                         The decision to choose a particular measuring accuracy is guided by the appli-
                   here. Measuring errors can occur even in “stagnant air” in recesses, above cold
                                                                                                         cation. As a rule, more accurate probes also mean higher investment. For the
                   shelves for vegetables and in niches.
                                                                                                         purpose of check measurements in the retail food industry, a whole-number
                                                                                                         temperature (e.g. -18 °C) or a relative humidity range (e.g. 50 – 60% RH) is used
                                                                                                         for nearly all applications. To ensure reliability of measurement, the accuracy of
                         The probe takes longer to reach the ambient temperature when measur-
                                                                                                         the probe should be below the parameter to be checked. In other words,
                   ing relative humidity and air temperature. If you are measuring in stagnant air,
                                                                                                         temperature should be measured in tenths and relative humidity in percentage
                   move the probe slightly to reduce the equalization period. Avoid direct sunlight,
                                                                                                         increments to ensure sufficient accuracy of determination.
                   proximity to surfaces with a different temperature (heating or refrigerating equip-
                   ment) and proximity to ventilation inlets. Even a temperature difference of just a
                                                                                                         3.8       Display unit
                   few tenths of a degree between the probe shaft and ambient temperature will
                   distort the measurement result.                                                       Portable instruments combine the control keys, power supply and the display
                                                                                                         itself in the display unit. Inside the measuring instrument, the electrical signals
                   3.7       Accuracy data                                                               from the sensor are converted into a value which can be read off and displayed
                                                                                                         on the display. Although a number of different types of instrument are available in
                   How accurately a probe can measure is described by the accuracy data. These
                                                                                                         the same housings, the technical equipment varies from one type to another. The
                   are shown in various ways in manufacturers’ catalogues. The simplest datum is
                                                                                                         decision which instrument to choose should be based on the technical perform-
                   absolute deviation. Absolute deviation is indicated in the unit shown, for instance
                                                                                                         ance data. This includes the choice of possible parameters. Modern instruments
                   degrees Celsius (°C). There are also percentage data related to the respective
                                                                                                         are able to recognize different probes automatically and output the correspon-
                   reading (% of reading); the absolute accuracy of the probe thus declines as the
                                                                                                         ding readings. The possibility of upgrading by adding a protocol printer should
                   temperature rises. These two pieces of data may also be combined to form an
                                                                                                         also be considered. This avoids tedious writing out and prevents copying errors.
                   accuracy datum with an absolute and a percentage component. There are also
                   accuracy data by class, which indicate the design of probe used. The table be-
                                                                                                         The accuracy of the display unit, or its “resolution”, is determined by the number
                   low shows an example of some common temperature levels.
                                                                                                         of subdivisions of the measuring unit that can still be read off. With digital instru-
                                                                                                         ments, the last digit of the reading may jump one unit. This inaccuracy is referred
                                                                                                         to as ±1 digit (from: digital unit).




28                                                                                                                                                                                                  29
     Parameters in the food industry                                                                                                                                Documents and records

                                      Reading at      Inaccuracy               Reading          4.        Documents and records
                                      25.342 °C
                   Resolution 0.1     25.3 °C            ± 1 digit           25.2…25.4 °C       The issue of logging is clearly set out, particularly in EU directives. Each meas-
                                                                                                urement includes the documentation of the results and where applicable the
                   Resolution 0.01    25.34 °C           ± 1 digit           25.33…25.35 °C
                                                                                                evaluation of the measurement data. If protocols are also inspected by the au-
                   Resolution 0.001   25.343 °C          ± 1 digit           25.342…25.344 °C   thorities, as is customary as part of the official food controls, complete and clear
                                                                                                documentation provides evidence. Therefore:
                                        Table 2: Accuracy of display units                      “If it isn’t documented, it doesn’t exist!”

                                                                                                Examples of protocols will be found below and in the appendix. Using modern
                                                                                                measuring technology such as data loggers or automatic measuring systems, it
                           Important: the accuracy of the measuring system as a whole is the    is also possible and usually accepted practice to store the data on the PC and
                   sum of the accuracy of the probe and the display unit. Make sure that the    use the programs provided by the manufacturer for evaluation. It is often no
                   probe corresponds to the display. The most accurate probe is no use if the   longer necessary to print out all measurement data and document it in the con-
                   resolution is too low.                                                       ventional way. Filing on the PC (with appropriate back-up of data) is sufficient.

                                                                                                Date and time
                                                                                                Data and time are absolutely necessary entries to allow traceability of documents
                                                                                                and products.

                                                                                                Contact person
                                                                                                If there are any queries, the designated contact person must be identifiable. Ini-
                                                                                                tials will suffice in small companies.

                                                                                                Location
                                                                                                It must be possible to retrospectively match the readings to the place at which
                                                                                                they were taken. In some circumstances, a sketch of the site or an exact de-
                                                                                                scription in relation to permanent fixtures, such as entrance doors, can be en-
                                                                                                closed.

                                                                                                Measuring equipment
                                                                                                The measuring instrument and probe used must be specified. This is the only way
                                                                                                to ensure that the accuracy of the measurement can be assessed retrospectively
                                                                                                and be compared with subsequent measurements.

                                                                                                Comments
                                                                                                Any unusual effects which could alter the reading, such as the failure of plant and
                                                                                                equipment, particular whether conditions etc., are noted here.

                                                                                                Actual value
                                                                                                The reading(s) taken.
30                                                                                                                                                                                          31
     Documents and records                                                                                                                                                                              Documents and records

                 Nominal value
                 The desired or required value at a measuring point, if specified on a plan or in a           Date                    Time               Delivery note no.                       Contact person
                 set of instructions.

                 Discrepancy between nominal value and actual value
                                                                                                            Incoming goods, fresh fruit and vegetables    Packaging intact + clean
                 If discrepancies are recorded in a protocol, appropriate corrective action must
                                                                                                            Incoming goods, dairy products                Container intact + clean
                 be taken. For this, the person recording the values must have the authorization
                                                                                                            Incoming goods, chilled goods, loose          Quantity as ordered
                 to perform independent corrections on the equipment concerned (i.e. the em-
                                                                                                            Incoming goods, frozen food                   Goods as ordered
                 ployee must be familiar with the machines and know how to operate them) or
                                                                                                            Incoming goods, dry packaged goods            Comments:
                 know where to turn if he cannot perform the measures himself. This may be the
                                                                                                            Incoming goods, consumer goods                ......................................................
                 case with technical changes to plant and equipment. If maintenance agreements
                                                                                                            Other incoming goods                          ......................................................
                 are in place, the contact persons, or in the case of outside installers the appro-
                 priate department, must be known.
                                                                                                                           Temperature measurement according to check plan


                         A discrepancy always means corrective action, corrective action a
                 check to ascertain whether the corrective action was successful. This can
                 only be done by employees with the appropriate expertise and authority.

                 User-friendliness or self-declaration are decision criteria with regard to the use of                                                       Mean value
                 protocols. For some applications (recording temperatures or air flows, air condi-
                 tioning system parameters), forms which refer to pre-defined measuring meth-
                                                                                                            Goods accepted                                       Supplier’s countersignature
                 ods already exist. These are not available for use in the retail trade and in most
                                                                                                            Goods rejected                                       ..........................................
                 cases are only suitable for technical issues. The protocols shown below can be
                 taken from the appendix or be recreated individually in a modified form.
                                                                                                                                  Table 3: Simple incoming goods protocol
                 4.1       Documents in the Incoming Goods department
                                                                                                         requirements of the product groups. For further quality assurance, the external
                 Protocols used in Incoming Goods should be kept simple so that any employee             appearance of the consignment may also be assessed. In the meat industry, the
                 can fill them in correctly. A simple structure should make them quick to complete.      additional assessment extends to the delivery personnel and the vehicle as well,
                 Multiple choice-type protocols which can be filled in by putting a cross in the ap-     and may be very detailed. It can be done at the same time as the measurement
                 propriate box have proved useful in practice.                                           if there is already close contact with the delivery and the supplier. This has not so
                 The Incoming Goods protocol therefore generally also includes the points listed         far been the case in retail, as individual companies often do not carry out contin-
                 in the previous chapter. The frequently recurring situations are listed with check-     uous supplier assessment.
                 boxes. It is a good idea to quote delivery note numbers to allow protocols to be        From the point of view of the consignee’s legal position, the first step should be
                 linked up to the relevant commercial and legal documents. Companies that do             to check immediately that the consignment is complete and undamaged. The
                 not have a supplier organization of their own may need to show their suppliers          actual temperature measurement is the labour-intensive part of the inspection
                 by name. Due to the fundamental importance of check measurements, the con-              and should be carried out immediately on delivery, at the time of transfer of risk
                 tact person must be identifiable. Initials or a signature are sufficient here.          in law. If more than one delivery is made at the same time, economic efficiency
                 All protocols refer to a basic check plan which can be structured according to the      requires the availability of a fast and accurate measuring instrument.


32                                                                                                                                                                                                                              33
     Documents and records                                                                                                                                                 Documents and records

                 The instruction of employees in the use of such protocols may form part of the       4.2       Documents as part of self-assessment
                 in-house training which the operator is required to provide in any case.
                                                                                                      A large number of measurements inevitably has to be made as part of self-
                                                                                                      assessment or when taking an initial inventory of the situation. Since very few
                 The above protocol only includes the most important points. The data are re-
                                                                                                      firms have complete and up-to-date documentation on room conditioning, the
                 quested in the widely-used order of Date, Time, Reference, Contact person. This
                                                                                                      person in charge should initially determine the appropriate measuring points him-
                 forms the basis for chronological filing, which can be further arranged according
                                                                                                      self to enable meaningful check measurements to be made. Various areas in the
                 to different criteria. The group of goods is selected. This group determines the
                                                                                                      sales room and store rooms are used in the retail food industry (see Table 4).
                 form of inspection and the check plan (cf. 4.4).
                                                                                                      The measuring methods involved are those used to assess the room air condi-
                                                                                                      tions. A large number of examples will be found in the field guide “Hygrometric
                 The check required by law to ensure that the goods are complete and intact can
                                                                                                      measurements for practitioners”, published by Testo, order no. 0980.0453.
                 be carried out during temperature measurement, in direct contact with the
                 goods. Any comments should be added to the log. While the measuring instru-
                 ment is adjusting, the inspector should assess the consignment for damage or
                 contamination. The inspector will be guided by the sequence of measurements
                                                                                                      Storage area                                   Approx. temperatures
                 made at representative points. If the purchase order is to hand, the quantity and
                                                                                                      Dry goods                                           £ 25 °C
                 description of the goods can also be checked. If a shortfall is discovered, the
                                                                                                      Fresh vegetables                                    £ 10 °C
                 measurement can be suspended and the goods rejected. The shortfall is docu-
                                                                                                      Fresh fruit                                         £ 10 °C
                 mented and the protocol countersigned by the supplier as a valid record.
                                                                                                      Self-service cold shelves
                 An important issue in this respect is training inspectors and giving them authori-
                                                                                                      (dairy products, cakes and pastries)                £ 10 °C
                 ty to reject defective goods. This may take the form of a notice with the name of
                                                                                                      Cold shelves (meat and poultry)                     £ 7 °C
                 the inspector, which is posted in the incoming goods area for the supplier to see.
                                                                                                      Cold shelves, loose goods (meat products, cheese)   £ 10 °C
                 Suppliers should be notified that a checking system of this kind is being intro-
                                                                                                      Fridges (drinks)                                    £ 10 °C
                 duced. If the purchaser does not have specifications already drawn up, these
                                                                                                      Cold rooms (store room)                             £ 7 °C
                 should be stated on the purchase order where necessary, for example: “Frozen
                                                                                                      Upright freezers (frozen food)                      £ 18 °C
                 food to be delivered at a temperature of -18 °C”.
                                                                                                      Chest freezers (frozen food: ice cream, vegetables,
                                                                                                      fruit, meat, fish, seafood and pastries)            £-18 °C

                                                                                                                      Table 4: Storage areas in the retail food industry


                                                                                                      4.3       Check measurements on plant and equipment
                                                                                                      As well as the receiving inspection, monitoring plant and equipment is necessary
                                                                                                      for operational safety. Refrigerating equipment, cabinets and chest freezers in
                                                                                                      particular are widely used in the retail trade to store high-value products. Regu-
                                                                                                      lar checks are required to ensure that these are always fresh. Although manu-
                                                                                                      facturers of refrigerating equipment often equip their products with display units,
                                                                                                      the temperature must be recorded in order to be able to detect fluctuations or
                                                                                                      failures over time. Data loggers are ideal for this.



34                                                                                                                                                                                                 35
     Documents and records                                                                                                                                                      Documents and records


                                                                                                           Adopting prescribed methods
                                                                                                           Following the standardization of European food law, uniform standards have
                                                                                                           been created with specific regulations that set out methods in far greater detail
                                                                                                           (e.g. documentation or observance of cooling chain) than before. A separate
                                                                                                           check plan can be drawn up from the processes set out in these standards, for
                                                                                                           example. However, the directives and regulations do not specify in detail how to
                                                                                                           proceed, they simply set out the basic parameters. It is therefore often necessary
                                                                                                           to match individual operating procedures against the specifications and draw up
                                                                                                           a specific plan.

                                                                                                           Bought-in method
                                                                                                           This method involves using ready-made check plans devised by someone else.
                                                                                                           Possible sources are government or association publications and information
                       Figure 12: Convenient checking of chest freezers using data loggers                 from measuring instrument manufacturers. The advantage of this method is that
                                                                                                           check plans are available quickly and generally inexpensively. Furthermore, such
                                                                                                           documents can be implemented within a short space of time in order to assess
                 4.4        Quality control plan                                                           their usefulness to the company. This compensates to some extent for the draw-
                 A check plan is a set of standard operating procedures which are applied in               back that not every individual requirement can be taken into account when de-
                 accordance with fixed rules. For example, you are following a simple check plan           vising the plans. The more expensive alternative is to hire an external consultant
                 if you check the oil level in your car engine regularly. The time (every three months),   to produce check plans. This is really only an option for larger companies or
                 location (engine compartment) and agent (yourself) are predefined. The nominal            associations. The protocols compiled in this guideline can be regarded as bought
                 value (minimum/maximum mark) and the actual value (oil level on the dipstick)             in. The appendix contains three forms which can be enlarged as required and
                 are compared.                                                                             used as copies for a first test run. Due to the limited space available, the most
                 In the case of a deviation, corrective action is taken - in this case, this is usually    common measuring methods have been selected.
                 topping up the oil. As with a vehicle, you can establish your own check plan for          Everyday use in situ should be explained to employees, put into practice and
                 your applications yourself, within appropriate limits. There are several ways of          established, irrespective of which method is used to devise check plans. If
                 devising a check plan:                                                                    employees are not yet carrying out checks, in-house training should certainly be
                                                                                                           provided. A distinction is made between the following phases:
                 Empirical method
                 Observation reveals sensitive points where experience shows that problems are             Awareness-raising phase
                 likely to occur first. It is not really possible to document this method, because it      Information provides a link between the importance of checking procedures for
                 is difficult to trace back how the choice of a particular location was reached. If the    personal safety and their economic significance. Existing stock management
                 official inspection bodies take a different view, disputes may arise.                     procedures and internal quality control can be developed further.


                 Statistical methods                                                                       Implementation stage
                 If statistical methods are used, as many measurements are taken as necessary              The practical use of measuring instruments and protocols is demonstrated, car-
                 to establish the reference between a representative location and the values               ried out under supervision and finally put into practice on the individual’s own ini-
                 throughout the measuring range with a high degree of probability. This method             tiative. This is where any shortcomings in the equipment or clarity of the protocols
                 is relatively complex and is mainly relevant to technical and scientific applications.    will become apparent. Different measuring instruments can be tested as well in or-
                                                                                                           der to establish that the instruments are working to the required performance.
36                                                                                                                                                                                                      37
     Documents and records                                                                                                                                                        The HACCP concept

                 Stabilization phase                                                                   5.        The HACCP concept
                 The use of measuring instruments and protocols becomes routine. Feedback on
                 results (discovery of where limits have been exceeded, machine malfunctions           The aim of a HACCP concept is to prevent defects arising through appropriate
                 etc.) is given. Continuous staff information through notices is a particularly use-   inspection and control procedures. This system was developed in the 1960s in
                 ful means of ensuring vigilance at all times.                                         connection with space travel. Today, it is regarded as a suitable tool for risk analy-
                                                                                                       sis. The biggest weakness of the system for the individual user is that every
                 Improvement phase                                                                     company has to develop its own system for its own business. There are no com-
                 User feedback enables equipment designs or configurations to be optimized,            plete ready-made instructions or detailed specifications; instead an analysis has
                 protocols simplified and measuring intervals adjusted. The result is “dynamic         to be carried out in situ.
                 checking” adapted to the situation.                                                   Implementation of the inspection and safety measures produces the operational
                                                                                                       system. The basic principles of this system of evaluation came from food
                 4.5       Dynamic checking                                                            production and packaging. In the retail food industry, the situation is simpler.
                 Adjusted checking means that the checking cycle has been adapted to the cir-          Retail outlets receive products and
                 cumstances. What this means in practice is that “good” equipment and suppli-          goods of a specified quality to sell to
                 ers are checked less often than the “bad” ones. “Good” is a criterion which you       consumers. In most cases, this does
                 can define for yourself. The basic yardstick should be compliance with the limits     not involve any processing or pro-
                 laid down by the authorities. How far you wish to exceed these depends on eco-        duction as such, but rather present-
                 nomic considerations and your customers’ expectations.                                ing goods according to customers’
                                                                                                       requirements. This covers a range of
                                                                                                       activities from offering cold cuts for
                                                                                                       sale to setting up displays of pal-
                                                                                                       letized goods for self-service.
                                                                                                       In a process of this kind, the control
                                                                                                       procedures are therefore confined to
                                                                                                       buying in goods in perfect condition
                                                                                                       and monitoring correct storage con-
                                                                                                       ditions. Additional hazards can be
                                                                                                       avoided by proper organization of
                                                                                                       operations, i.e. keeping foodstuffs
                                                                                                       physically separate from household
                                                                                                       chemicals, providing detailed con-
                                                                                                       sumer information, correct labelling
                                                                                                       to avoid confusion or incorrect Figure 13: Reliable checking, including of
                                                                                                       handling and taking precautions to small products, in Incoming Goods
                                                                                                       prevent sabotage.
                                                                                                       The design and and layout of buildings and industrial hygiene in general are also
                                                                                                       involved here, although these will not be discussed in further detail here. The key
                                                                                                       aspect of the HACCP concept is monitoring physical parameters. Due to its enor-
                                                                                                       mous significance for the stability of food, temperature monitoring is the most
                                                                                                       effective weapon for an efficient quality assurance system.

38                                                                                                                                                                                                    39
     The HACCP concept                                                                                                                                                               The HACCP concept

                Products that have been incorrectly handled are rejected at the receiving stage           possible danger to health from microorganisms, chemicals or splinters, for
                if they have not been transported under the specified conditions. Dirty or                example, and the risk, i.e. the probability of a health hazard occurring.
                damaged packaging is just as detrimental to the operating procedure as goods              Temperature control, for instance check measurements of meat, meat products,
                not transported under the right conditions, due to the cost of disposal, pecuniary        delicatessen foods (£7 °C), frozen food (£-18 °C) and baked goods with a part-
                loss and premature spoiling. Furthermore, the documentation offers a helpful              ly cooked filling (£10 °C, recommended temperature) prevents goods that have
                basis for dealings with the official supervisory bodies. This of course also involves     been incorrectly transported from being delivered.
                extra work, which can be kept to a reasonable level by using ready-made check             In the area of packaging and labelling, the aim is generally to prevent risk by pro-
                lists, check plans and specimen protocols. The resulting reassurance benefits all         viding product information where required. If particular products by their nature
                the company’s employees.                                                                  carry a certain microbiological contamination, the health hazard can be kept to

                5.1        Applications in the retail food industry
                Anyone handling food, in either production or distribution, has a huge responsi-
                bility towards the consumer. Extensive information has made the consumer
                increasingly aware of quality and health issues. Both the industry and the legis-
                lator are responding by developing in step. Quality certificates, proof of origin and
                delivery protocols are essential today to comply with the ever-stricter legal re-
                quirements and provide the authorities with the required proof.
                 The retail food industry is the last link in the production and distribution chain and
                is the point of contact with an enormous number of customers. And it has to of-
                fer that large number of customers a balanced range of foodstuffs which in some
                cases spend a long time in the sale process and pose different requirements for
                correct storage. The most important physical influences during storage are time,
                temperature and relative humidity. Monitoring and logging these, and correcting
                them where necessary, is the task of the manager of the company or department.
                As the retail food industry generally buys in goods of a specified quality, the obli-         Figure 14: Inspection of a cold shelf for sufficient refrigerating capacity
                gation on companies to implement self-inspection extends to the bought-in
                products it offers for sale. Furthermore, the compliance with statutory require-          a tolerable level through correct storage. Since many products spend a large
                ments increases the scope for transferring liability to the suppliers upstream in         part of their life cycle on display at the retailer’s, hygienic storage and monitoring
                the event of a legal dispute. Self-inspection is therefore one of the bases of            of storage conditions are very important.
                economic survival for any food distributor.                                               Apart from the physical parameters of temperature and relative humidity, migra-
                The analysis can be carried out on the basis of flow charts produced from eval-           tion of pollutants, immissions and pest infestation can also present hazards. The
                uation questionnaires and specimen protocols. Check lists can also be used as             risk can be kept to a tolerable level by developing a tailor-made hygiene system.
                an evaluation tool, to assess the environment or organize stock, for example.             The aspects to be monitored are determined as part of the HACCP concept and
                The documents produced as part of a risk analysis also serve as proof to the              the inspection tools (measuring instruments, inspection procedures), intervals
                official food inspectorate. Due to the changed legal position, their maxim is now         and logging procedure are specified. Monitoring of these aspects documented
                “inspecting inspection”, in other words appraising the self-inspection in place.          over a long period gives the retailer proof of the duty of care required by law. Ev-
                For the retailer, the question is how to develop and operate such a system. A             idence of a documented HACCP concept which can be submitted in the case
                distinction has to be made between the hazard, i.e. the actual occurrence of a            of product liability issues is also useful.




40                                                                                                                                                                                                       41
     The HACCP concept                                                                                                                                                     The HACCP concept

                The main points of EU Regulation 852/2004:                                        Steps and actions implemented (including readings, for example) must be ade-
                                                                                                  quately documented and be submitted to the relevant authorities on request. The
                     Obligation to observe a general and specific requirement to ensure perfect   documents and records must be kept for an appropriate period of time.
                     hygiene conditions at all stages of food production
                                                                                                  The obligation to train employees is not new, but has been described in consid-
                     Obligation to carry out risk analyses and set up self-inspection systems     erably more detail. Every company must provide its employees with adequate
                                                                                                  and appropriate training. Training also has to be documented. For example,
                     Obligation to observe appropriate measures of Good Hygiene Practice          exercises can be done using specimen protocols which at the same time serve
                     (GHP)                                                                        as proof that the training has been carried out. It is in the company’s interest to
                                                                                                  organize regular refresher courses, to check the skills of its employees. It is
                     Establishment of a self-inspection system to HACCP standard                  easiest to train new employees and temporary staff in particular if they have writ-
                                                                                                  ten documents to refer to. It must also be ensured that the documents from which
                     Obligation to train employees                                                these processes have been developed are up-to-date at all times. Official
                                                                                                  inspections of training documents and checks to ensure that training has been
                     Documentation                                                                carried out can be made.




42                                                                                                                                                                                             43
     Technical background information                                                                                                                       Technical background information

                  6.        Technical background information                                              Platinum resistance sensors (Pt100)
                                                                                                          This method of measuring differs in principle from thermocouple probes.
                  6.1       Temperature sensors (design/operation)                                        Platinum resistance sensors essentially work on the basis of what is called the
                                                                                                          “PTC resistor”. Metals have the property of increasing their electrical resistance
                  Thermocouples                                                                           as the temperature rises. This property can be used to measure temperatures.
                  The measurement of temperatures using thermocouples is based on the                     A wafer-thin wire of the high-purity metal, plat-
                  thermoelectric effect. An electric current will flow in a circuit if the conductor is   inum, is wound around a slender glass tube (one
                  made up of two different alloys and their points of contact are at different            possible design) until a specified resistance is
                  temperatures. If the temperature at one point of contact is known (reference            reached. The most common resistance value to-
                  point), the “thermoelectric voltage” present is a direct measurement of the             day is 100 W (unit of electrical resistance) at 0 °C.
                  difference in temperature between the measuring points (hot end) and the                This is known internationally as a PT100 sensor.
                  reference point (cold end). The two wires of the thermocouple are also known as         Another design for a Pt100 sensor is a ceramic
                  a branch or thermocouple pair. The thermocouple is made from copper/                    carrier material (small leaf) onto which a platinum
                  cupronickel (Cu-CuNi). These thermocouples are also known internationally as            structure is etched. Sensors made in this way are extremely compact. Probes
                  type T. The cold end (reference point) of a thermocouple measuring chain which          with platinum resistance sensors are among the most accurate sensors avail-
                                                                                                          able. They are long-lasting and non-ageing. However, their response time is sig-
                                                        Weld                                              nificantly slower than that of thermocouples due to the design. They are used in
                                                                                                          food technology, particularly in laboratories.
                                                                           Thermal material 1,
                                                                           e.g. NiAl
                                                                                                          Thermistor sensor (NTC)
                                                                                                          Thermistors are modern, inexpensive temperature sensors made from mixed
                                                                                                          oxide ceramic. Their resistance falls as
                                                                                                          the temperature rises. They therefore
                                                                                                          behave in exactly the opposite way to
                                                                                                          Pt100 sensors. NTC sensors are inex-
                                                                                                          pensive, accurate and suitable for
                              Thermal material 2,
                              e.g. NiCr                                                                   many applications in the food industry.
                                                                                                          Measuring instruments using NTC sen-
                  Example: Thermocouple principle                                                         sors do not require reference point ad-
                                                                                                          justment (see thermocouples). This
                  we have just mentioned always refers to 0 °C. With electronic thermometers, this        makes them ideal for use in cold rooms and refrigeration chambers.
                  reference is calculated electronically by measuring the ambient temperature in-
                  side the thermometer. Because the temperature sensor at the reference point
                  needs some time to adjust to the ambient temperature, care should be taken
                  when measuring in a cold environment to allow sufficient time for the thermome-
                  ter to adjust. This may, for instance, be the case if the thermometer has been left
                  in a car overnight (temperature +5 °C, for example) and is then taken into a room
                  at +25 °C. Conversely, it is also important to give the thermometer a few minutes
                  to adjust when moving from a warm area (e.g. +10 °C) to a cold one. A stable
                  reading can only be taken once a certain period of time has lapsed.


44                                                                                                                                                                                             45
     Technical background information                                                                                                                       Technical background information

                  Comparison of sensor types                                                          6.3        Different designs of probe and their uses
                                                                                                      Different designs of probe are available for different applications. Just as a different
                                    Thermocouple          NTC                     Pt100               kind of knife is generally used to cut bread and meat, there are immersion/
                                    type T                                                            penetration probes, air probes and surface probes for measuring temperature as
                                                                                                      well as special designs of probe.
                  Meas. range       -50 to +350 °C        -50 to +150 °C         -200 to +400 °C
                                                          (in some cases up to +250 °C)               Immersion/penetration probes
                                                                                                      Probes of this type are designed specifically for measuring temperature in liquids
                  Response time Very fast                 Fast                    Slower              and viscoplastic substances such as meat, fish, dough etc. The tip of the probe
                                                                                                      is designed for insertion. Immersion/penetration probes are standard probes and
                  Accuracy          Accurate              Very accurate           Extr. accurate      can also be used to take measurements in air if the measuring instrument is giv-
                                                                                                      en sufficient time to adjust to the air temperature. The examples below give the
                  Uses              Allrounder            Cold rooms,            Laboratory           testo order numbers for ease of identification.
                                    for                   refrigeration chambers
                                    food serving,         monitoring of                               Example of a robust all-round temperature probe
                                    incoming goods,       transport,                                  (immersion/penetration probe) No. 0603.1293
                                    kitchen.              incoming goods
                                                          food serving


                  6.2       Sensor, probe, measuring unit
                  For technical reasons, the actual temperature sensor always has to be housed        Example of an immersion/penetration probe with an extremely fine measuring tip
                  inside a probe shaft. Fitted with a handle and a connecting cable, this is gener-   (leaves barely visible holes in meat, fish etc.)
                  ally referred to as a temperature probe. The temperature probe provides the         No. 0603.2693
                  measurement signal in the form of a voltage or resistance. However, the meas-
                  urement signal on its own is not a usable reading. A display unit (measuring
                  instrument) is needed to display it.
                  A measuring unit therefore always comprises a probe and a measuring instru-
                  ment.


                                                                                                      Example of stainless steel food probe (sturdy, very easy to clean)
                                                                                                      Note:     with conductor up to +80 °C for 0603.2192
                                                                                                                with conductor up to +205 °C (+250 °C briefly) for 0603.3392


                  Fig. 15: Measuring
                  air temperature on
                  refrigerated display
                  cases and chest
                  freezers
46                                                                                                                                                                                               47
     Technical background information                                                                                                                               Technical background information

                  Air probes                                                                             Which probe/measuring instrument for which application?
                  Air probes are specifically intended for measuring air temperatures in cold
                  shelves, chest freezers or store rooms, for example. The sensor is exposed and         What is being measured? Design – Probe                  h
                                                                                                                                                            Hand-held meas. instr. IR meas. instr.
                  therefore readily accessible to the air flow.                                          Steaks, escalope               Needle probe        testo 926
                                                                                                         pizza, fish fillet             Type 26
                  Example of a fast-response air probe
                                                                                                         Roast, half a pig,             Stainless steel probe testo 110, 112, 926
                  No. 0603.1793
                                                                                                         legs, sauces,
                                                                                                         purée, desserts...
                                                                                                         Frozen food in                 Frozen food probe testo 110, 112, 926 testo 826, 831
                                                                                                         incoming goods                 Type 32
                                                                                                         Frozen food, measurement Frozen food probe testo 110, 112                  testo 826
                  Surface probes                                                                         in deep freezer or       Type 32
                  A wider tip is needed to measure surface temperature (on packs, packaging,             deep freeze truck
                  frozen food, hotplates etc.).
                                                                                                         Air temperature in        Air probe                testo 110, 112, 926 testo 826, 831
                                                                                                         cold rooms, cold shelves, Type 17
                  Example of a surface probe (no. 0603.1993)
                                                                                                         chest freezers
                                                                                                         Core temperature in       Frozen food probe testo 110, 112                 testo 831
                                                                                                         cold rooms, cold shelves, Type 32
                                                                                                         chest freezers,
                                                                                                         shock frosting
                  Special designs of probe for measuring inside frozen food                              Receiving inspection           Stainless steel probe testo 110, 112, 926 testo 826, 831
                  To measure the temperature inside frozen food, a probe (penetration probe) must                                       Type 21, 22
                  be inserted into the food (core temperature measurement). As a rule, a hole must                                      Incoming goods probe
                  be drilled in order to insert the penetration probe (e.g. 0603.2192). The special
                                                                                                         Screening test                       –                     –               testo 826, 831
                  design of the frozen food probe (no. 0603.3292) has a “drill tip” for easy insertion
                                                                                                         (quick test) in cold shelves
                  into frozen food. The sensor is at the front of the measuring tip. Insertion pro-
                                                                                                         on milk, yoghurt,
                  duces close thermal contact with the material. The connecting cable is detach-
                                                                                                         vacuum-packed products
                  able to prevent twisting during insertion. The testo 105 measuring instrument
                  consists of the frozen food tip and display unit in a compact unit (no. 0563.1051).



                                                                                                         6.4        Infrared measuring instruments/infrared probes
                                                                                                         What are known as infrared thermometers can measure temperature contact-
                                                                                                         lessly. However, due to the nature of the system, only the surface temperature is
                                                                                                         measured, and not the core temperature. The measurement result is extremely
                                                                                                         dependent on the surface of the goods/packaging to be measured. Larger
                                                                                                         measurement errors occur in measurements on ice crystals and on polished and
                                                                                                         reflecting surfaces.

48                                                                                                                                                                                                     49
     Technical background information                                                                                                                          Technical background information

                  How does infrared measurement technology work?                                           Carton packagings should be opened and the measurement taken inside the
                  Every object warmer than the absolute zero point temperature (-273 °Kelvin)              packaging. Do not measure on the outside of the box.
                  gives off heat energy. This heat energy is in the infrared range which is not visible
                  to the human eye. Using special optical sensors, this heat energy can be
                  measured and the temperature can be displayed.

                  Radiation capacity, emissivity
                  Each body made of different materials (ceramic, glass, steel, stone, food etc.) has
                  a different radiation capacity (emissivity) for heat energy. The ratio for how well
                  heat energy is given off is known as the emissivity. It is described by the Greek
                  letter e. The emissivity value in food only fluctuates slightly between 0.90 and
                  0.98. Since a fluctuation of this magnitude in the emissivity only causes a mini-
                  mal change in the temperature displayed, it can generally be ignored. However,
                  if the temperature is measured on polished or shiny metals, the emissivity is sig-       In the case of food wrapped in cling-film, only the temperature of the film is meas-
                  nificantly lower (typically 0.05 to 0.2). In this case, emissivity has to be increased   ured. You should therefore only measure at points which are in direct contact
                  by applying emission adhesive tape, for example; otherwise, measurement                  with the food.
                  errors of up to 50% are possible.

                  Where are infrared measuring instruments appropriate, where not?
                  Infrared measuring instruments are ideally suited for quick checks (screening
                  test) in the incoming goods department, in cold shelves or in chest freezers. If
                  there are fluctuations in the temperature, the exact temperature value must be
                  measured using a core temperature
                  measuring instrument. Infrared measur-
                  ing instruments are not ideal for prod-
                  ucts in carton packagings that cannot
                  be opened (pizza, spinach, ready-to-
                  cook vegetables etc.) since they only
                  measure the outside of the packaging                                                     Compact infrared measuring instruments with measuring spot marking
                  and not the product inside. If in doubt,                                                 testo 831 is the name of an easy-to-use infrared measuring instrument suitable
                  always carry out a core temperature                                                      for food technology. As well as the reading, minimum and maximum values are
                  measurement.                                                                             also recorded. A (variable) upper and
                                                                                                           lower limit can be set on this instrument
                  Infrared temperature measurements on packaged goods                                      which will generate an acoustic alarm
                  The ideal distance between the measuring instrument and product/packaging is             signal if exceeded or undershot. Anoth-
                  within a range of 5–15 cm.                                                               er special feature is the way in which a
                  If the distance is greater, the measuring spot should not be bigger than the prod-       measuring spot is marked. 2 laser
                  uct/packaging. Refer to the instruction manual for information about the size of         beams mark the area where the read-
                  the measuring spot. With modern instruments, accurate measurements can still             ings are to be taken. In contrast to
                  be obtained at distances of 30 cm–1 m.                                                   single-beam instruments, it is not just
                                                                                                           one measurement point but a measur-
50                                                                                                                                                                                                51
     Technical background information                                                                                                                    Technical background information

                  ing area that is displayed, enabling the user to see exactly where temperatures     6.5       Measuring instrument with data memory, product
                  are being measured.                                                                           assignment and printing function
                                                                                                      Special measuring instruments with a data memory function, product assign-
                  Example: 30:1 lens of testo 831                                                     ment and a documentation function are available for convenient, routine meas-
                                                                                                      urements in the Incoming Goods department, store room or when serving food,
                                                                                                      for example. The requirements of HACCP are easily and fully met if these instru-
                                                                                                      ments are used. One such instrument is testo 735, which is described below:
                                                                                                      Different probe types can be connected to the inputs of the testo 735 multi-func-
                                                                                                      tion measuring instrument. The advantage of
                                                                                                      this is that the probe ideally suited to the meas-
                                                                                                      uring task can be selected and used. It is there-
                                                                                                      fore possible to connect what are referred to as
                                                                                                      thermocouple probes (type T) to one input sock-
                                                                                                      et and Pt100 probes to the other input socket.
                                                                                                      The quick-action type T probes are ideal for a rel-
                  Infrared beams may not be visible to the eye,                                       atively constant ambient temperature as, due to
                  but they conform to the laws of optics. This                                        the measuring principle, the display electronics
                  means that an infrared measuring instrument                                         take anything from a few minutes to half an hour
                  has the smallest measuring spot diameter                                            (depending on how heavily the ambient temper-
                  close to the infrared lens and that the measur-                                                                                         Fig. 17: Displaying location
                                                                                                      ature fluctuates) to “adjust”. One advantage is
                  ing spot will get larger the further away it is from                                                                                    and parameter. Up to 99% of
                                                                                                      that the thermocouple probes can be used to
                  the lens. An easier way to imagine this is to                                                                                           product names can be stored
                                                                                                      make special probe designs, such as probes
                  think of the light beams of a flashlight (but the                                                                                       in the instrument.
                                                                                                      with an extremely fine measuring tip (needle
                  other way round). The relationship between the                                      probe). Pt100 probes are slightly slower in their
                  measuring distance and the diameter of the                                          response time, but the analysis electronics are not affected by fluctuations in am-
                  measuring spot indicates the quality of the lens                                    bient temperature. Precedence is therefore given to these probes in areas where
                  used and is often shown as a ratio. Example:                                        the ambient temperature fluctuates strongly, for example in the Incoming Goods
                  10:1 means that with a distance of one metre                                        department or in the cold storage house.
                  the anticipated measuring spot is roughly 10%
                  of the distance, so 10 cm. A 30:1 lens would                                        Saving, printing and analyzing data
                  only have a measuring spot of around 3.6 cm          Fig. 16: Infrared instrument   Temperature values measured by the probe are immediately shown in the
                  on a distance of one metre.                            with switchable close-/      display. The displayed temperature value can be saved in the memory at the
                  Particularly advanced instruments have the                long-distance lens        touch of a button. With testo 735, it is possible to store up to 99 different
                  facility to change the focussing point of the                                       product names in the instrument (via PC) for easy analysis and clear assignment
                  lens. It is therefore possible to generate an extremely small measuring spot at a   of this data. Any location can be selected using the cursor keys on the instrument
                  close distance (e.g. a few mm at a measuring distance of 20–30 cm) and to           in order to assign subsequent data to this location or product.
                  also measure at long ranges with a switched lens. The testo 845 is an example
                  of such an instrument.




52                                                                                                                                                                                          53
     Technical background information                                                                                                                       Technical background information

                                                                                                       6.6       Data loggers
                                                                                                       If the requirement is not merely to measure data on the spot but to make obser-
                                                                                                       vations over a longer period, what are known as data loggers are used.

                                                                                                       What is a data logger?
                                                                                                       • A data logger is an electronic measuring instrument with a built-in memory and
                                                                                                         clock.
                                                                                                       • A data logger records a reading at fixed intervals to be set by the user (e.g. every
                                                                                                         10 minutes, every 30 minutes etc.) and stores it.

                                                                                                       If a limit value set on the PC is exceeded, an acoustic signal is generated or a pi-
                                                                                                       lot light starts to flash. This makes it the ideal way of monitoring cold rooms, chest

                                  Fig. 18: Receiving inspection with data storage
                                                                                                                           Measuring                                             PC
                                                                                                        Sensor                                          Memory
                                                                                                                           technology                                         interface
                  An upper and lower limit value can also be added for each product name (again,
                  during programming on the PC). A optical and acoustic alarm is activated if this
                  value is exceeded or undershot. The specified limit values are of course also                                                         Clock
                  included in the printed protocol.
                  Printing is started on the Testo protocol printer, available as an accessory, by
                  pressing the “Print” button. A document with an information line, date, time, tem-
                  perature and limit values is therefore immediately available.
                  Data analysis is even easier if a PC is available. The data blocks of a product or
                  the complete memory can be read into the PC where they can be analyzed in
                  graph or tabular form. If the data measured on one day is saved on an appropri-
                  ate data carrier, you then have long-term documentation which enables food
                  inspectors in particular to view all the data without any gaps, and the operator
                  shows that he is fulfilling his duty of care.




                                                                                                                           Fig. 19: Data logger with printing function

                                                                                                       freezers, cold shelves etc. Room climate monitoring (e.g. with a logger which can
                                                                                                       register temperature and air humidity) for warehousing processes is also made
                                                                                                       easy. Data loggers such as the testo 175 are very compact and handy and com-
                                                                                                       bine a low price with an extremely sturdy design. The data logger is programmed
                                                                                                       (pre-set) in the office via a PC. It can be started by means of an internal clock or
                                                                                                       by a button start on site. A fast printer on site will document the readings if
54                                                                                                                                                                                              55
     Technical background information                                                                                                            Tips for using the measuring instruments

                                                                                                        7.        Tips for using the measuring instruments
                                                                                                        7.1       Where is the best place to store the instrument?
                                                                                                        Store the instrument at ambient temperatures of between +4 and +30 °C.
                                                                                                        Storage in an office (department office, workshop etc.) is recommended –
                                                                                                        never store in the deep freeze section!
                                                                                                        If the instrument is only used for measuring in the Incoming Goods department,
                                                                                                        it can also be stored there. Advantage: the instrument always remains at the
                                                                                                        ambient temperature and does not need an equalization period.

                                                                                                        7.2       How do the measuring instruments react to fluctuating
                  required and can even be used to stop and restart the logger without using the
                                                                                                                  ambient temperatures?
                  PC. Another accessory is what is known as the data collector, which reads out
                  the entire data logger at the press of a button and buffers the data. Once you have   testo 110, testo 112, testo 105, testo 106:
                  arrived in the office, the various logger protocols can easily be read out and as-    Negligible influence of fluctuations in ambient temperature
                  signed using the software.                                                            (change: warm cold or cold warm).
                  Professional data loggers with a full metal housing are available for use over
                  longer periods (e.g. in cold storage houses, refrigeration chambers etc.)             testo 926, testo 826, testo 831:
                  A special feature of this instrument generation is a plug-in display unit which       If the instrument is only exposed to a cold environment briefly (1 to 2 minutes),
                  allows values to be read off during operation or printed out on site.                 the fluctuation in temperature is negligible. If the instrument is exposed for a
                                                                                                        longer time, it will need an equalization period of 15 to 20 minutes.
                                                                                                        Note: Instruments such as the testo 826 which are only specified for an applica-
                                                                                                        tion range of 0 °C to +50 °C should not be stored in the deep freeze section for
                                                                                                        a prolonged period of time. Incorrect measurements are to be expected when
                                                                                                        the instrument is switched on. It is recommended to store the instrument in warm
                                                                                                        ambient conditions and perform a short measurement (1 to 2 minutes) in the
                                                                                                        deep freeze section.

                                                                                                        7.3       How deep should a probe be inserted?
                                                                                                        Measurements with penetration probes on non-frozen food:
                                                                                                        In order for the heat to be transferred properly from the food to the probe, the
                                                                                                        probe should be inserted at least 5 times (even better 10 times) its diameter into
                                                                                                        the material.
                                                                                                        Example: Probe tip             = 4 mm diameter
                                                                                                                    Penetration depth = 4 mm x 5 = 20 mm
                                                                                                                                                                                 ø
                                                                                                        Measurements in frozen food with special probe:
                                                                                                        A special frozen food probe is available for measure-                        ‡5 x ø
                                                                                                        ments in hard, frozen food. It has a corkscrew tip. This
                                                                                                        is screwed in until the thread is no longer visible. En-
                                                                                                        sure that the piece of meat is large enough (at least 2
                                                                                                        kg weight) to be measured. Not suitable for pizza, steak, fillets etc.
56                                                                                                                                                                                            57
     Tips for using the measuring instruments                                                                                                    Tips for using the measuring instruments

                   How great might the measuring error be if the tip is not inserted deep enough in-   7.4       Measuring time
                   to the item being measured?
                                                                                                       When is a measurement complete?
                                                                                                       Each probe requires a certain amount of time to reach the final value for the food
                                             Set temperature = 0 °C                                    which it is measuring. The technical name for this value is the t99 time and it is
                                                                                                       given in catalogues and brochures. However, this value only refers to a meas-
                                12.2
                                                                                                       urement in water. This value is slightly higher in food (typically 15 seconds to 3
                                                                                                       minutes depending on the type of probe). There are two pertinent methods for
                                                                                                       practical application:

                                            3.8                                                        Stop measurement when the required value is reached
                                                                                                       The measurement can be stopped by the user if the required minimum value has
                                2.9
                                                       1.2
                                                                    0.5
                                                                                                       been reached. It is not necessary to carry on waiting for the actual final value.
                                                                                 0.2
                                                                                              0
                                                                                                       Example: Frozen food is delivered at an actual temperature of
                                           0.4         0.1           0                                 -21.5 °C. The required minimum value (food hygiene regulation) is
                                1 cm       2 cm       3 cm          4 cm          6 cm      8 cm       -18 °C + 3 °C = -15 °C (maximum temperature which may be reached briefly
                                                     Penetration depth in cm                           during loading). This means that if the thermometer used shows a temperature
                                                                                                       of -15.1 °C, the measurement can be stopped.

                                            Set temperature = -18 °C                                   Stop measurement once the display no longer shows any significant
                                                                                                       change
                                 -8.4
                                                                                                       For absolutely accurate measurements, it is recommended to continue with the
                                                                                                       measurement until the last digit in the display jumps by no more than ± 1 digit.
                                          -12.7                                                        In practice, the user sees a very quick and clear change at the beginning of the
                                                                                                       measurement (in the case of frozen food from +20 °C to 0 °C), then the rate of
                                                      -16.1                                            change slows down in the range of 0 °C to -12 °C and finally it “creeps slowly”
                                                                    -17.2
                              -14.8
                                                                                 -17.9      -18.2      towards the final value (-18 °C).
                                          -17.9        -18.2        -18.3        -18.3      -18.3
                                                                                                       7.5       Official calibration, calibration – who needs what?
                                1 cm       2 cm       3 cm          4 cm          6 cm      8 cm
                                                                                                       Anyone wishing to perform measurements on foods requires calibrated instru-
                                                      Penetration depth in cm
                                                                                                       ments. Calibration means comparing the measuring instrument with connected
                                                                                                       probe with a reference instrument and documenting any deviation on a calibra-
                        Probe type 22                                       Probe type 32              tion certificate.
                                                                                                       Official calibration essentially means “calibration by an authority”. The Board of
                                                                                                       Weights and Measures calibrates specially approved instruments and probes.
                                                                                                       The instrument and probe are given a calibration mark that is visible to the user.
                                                                                                       In this case the calibration certificate is called a calibration certificate issued by
                                                                                                       an accredited calibration laboratory. Food inspectors, veterinaries and other
                                                                                                       people working on behalf of the government need officially calibrated instru-
                                                                                                       ments.


58                                                                                                                                                                                              59
     Tips for using the measuring instruments                                                                                                             Tips for selecting measuring points

                                                                                                       8.        Tips for selecting measuring points
                                                                                                       Appropriate measurement points should be chosen according to the measuring
                                                                                                       task.

                                                                                                       8.1       Chest freezers
                                                                                                       As well as the product temperature, the air temperature in the freezer is relevant
                                     Fig. 20: Calibration mark on the instrument,
                                                                                                       here. It is advisable to measure the air temperature in the vicinity of the air recir-
                                 calibration mark on the probe, seal, homologation
                                                                                                       culation using a suitable probe (air probe). This is where the air is warmest. If the
                                                                                                       air here can maintain the correct temperature (e.g. -18 °C), the chest freezer can
                                                                                                       be assumed to be working properly. Data loggers with several input channels are
                   7.6       Documenting the measurement results                                       recommended for monitoring chest freezers over a longer period of time. One
                   For the purposes of quality assurance, many transport companies and suppliers       probe measures the air temperature at ground level, another at the maximum
                   record the temperature during transport using what is known as a data logger. If    load line, while a third measures the air temperature at the air recirculation. For
                   required, a printout can often be handed over on receipt of the goods. However,     simple monitoring, it is sufficient to place a data logger with an internal tempera-
                   the temperature probe in the truck only measures the storage compartment            ture sensor (e.g. testo 174 or 175-T1) against the frozen food.
                   temperature (temperature inside the truck at the height where the air is recircu-
                   lated). The temperature of the goods should also be measured in the Incoming
                   Goods department. The temperature measurement in trucks is therefore only
                   partly suitable or not at all suitable for receiving inspection tests.




                                                                                                                  Fig. 21: Measuring air temperature with a special air probe

60                                                                                                                                                                                              61
     Tips for selecting measuring points                                                                                                             Tips for selecting measuring points

                   8.2       Cold rooms, store rooms                                                   8.3      Serving food
                   As well as monitoring the air temperature and product temperature (random           At places where food is served, speed of measurement is essential. The use of
                   measurement of the core temperature of the chilled goods), the use of a data log-   fast-response probes (e.g. Testo penetration probe type 2692) is therefore
                   ger is recommended. Data recording is even mandatory for cold rooms and re-         recommended. The core temperature must be measured in order to see whether
                   frigeration chambers >10 m³. A suitable measuring interval is 15 minutes (e.g.      the food (mainly pieces of meat) has been heated to an even temperature
                   according to EN 12830). The limit values for a data logger are set to the maxi-     throughout. A minimum temperature of 65–70 °C is recommended.
                   mum acceptable temperature (-18 °C, -15 °C). Special logger designs allow the
                   basic temperature data to be read out (to test the testo 175 or 177 with infrared
                   printer, for example).
                   If overly high values are detected, the data logger can be read out on the PC. A
                   graph provides a precise picture of when the measurement data strayed over the
                   permissible limits and for how long.




                                  Fig. 22: Monitoring frozen food with a data logger                           Fig. 23: Serving food – core thermometer assures food safety




62                                                                                                                                                                                         63
64
     WHAT Incoming goods,                  Incoming goods,                 Incoming goods,
          frozen food                      frozen food                     frozen food
                                                Recommended measure-              Recommended measure-
                                                ment points                       ment points




            Box, single                   Boxes, stacked singly            Boxes, palletized
          • Digital thermometer with      • Digital thermometer with       • Digital thermometer with
            penetration probe               penetration probe                penetration probe
          • At three points along         • At three top points            • At three points along
     HOW/   the outer edges                 along the outer edges            the top outer edges
     WITH • At the centre:                • Twice at the centre between • Twice at the centre between
                                                                                                            User tips for monitoring temperature




     WHAT reseal                            the layers, insert probe fully the layers, insert probe fully
          • Prot.: Incoming goods,        • Prot.: Incoming goods,         • Prot.: Incoming goods,
            frozen food                     frozen food                       frozen food
     WHO:   • Incoming Goods Acceptance   • Incoming Goods Acceptance      • Incoming Goods Acceptance
     WHEN • Immediately on delivery       • Immediately on delivery        • Immediately on delivery
     HOW • 4 measurements:                • 5 meas. for 2 layers,          • 5 meas. for 2 layers,
     OFTEN per box                         2 measurements                   2 measurements
                                           for every additional layer       for every additional layer
           • Differences £ 2 °C           • Differences £ 2 °C             • Differences £ 2 °C
     VALUE • Mean value £ -18 °C          • Mean value £ -18 °C            • Mean value £ -18 °C




     WHAT Incoming goods,                 Incoming goods,                  Incoming goods,
          dairy products                  dairy products                   dairy products




            Containers, single            Containers, stacked              Containers, palletized
            • Digital thermometer with    • Digital thermometer with       • Digital thermometer with
             surface probe                 surface probe                    surface probe
            • Measure on four outside     • Measure on three outside       • Measure on three outside
     HOW/    product containers            product containers               product containers
     WITH    (surface)                     (surface) in the top             (surface) in the top
     WHAT   • Prot.: Incoming goods,       layer                            layer
              fresh produce               • Measure surface of every       • Measure surface of every
                                           additional layer twice           additional layer twice
                                          • Prot.: Incoming goods,         • Prot.: Incoming goods,
                                            fresh produce                    fresh produce
     WHO:   • Incoming Goods Acceptance • Incoming Goods Acceptance        • Incoming Goods Acceptance
     WHEN   • Immediately on delivery     • Immediately on delivery        • Immediately on delivery
     HOW   • 4 measurements per           • 5 meas. for 2 layers,          • 5 meas. for 2 layers,
     OFTEN container                       2 measurements                   2 measurements
                                           for every additional layer       for every additional layer
           • Differences < 1 °C           • Differences < 1 °C             • Differences < 1 °C
                                                                                                            User tips for monitoring temperature




     VALUE • Mean value £ 10 °C           • Mean value £ 10 °C             • Mean value £ 10 °C
65
66
     WHAT    Fresh produce,                Fresh produce,                  Fresh produce,
             meat, sausages                meat, sausages                  meat, sausages




             Box, crate, container,        Case, crate, container,         Case crate, container,
             single                        stacked                         palletized
             • Digital thermometer with • Digital thermometer with         • Digital thermometer with
               penetration probe             penetration probe               penetration probe
             • At three points along       • At three points along         • At three top corners
     HOW/      the outside wall              outside wall on the             along the outside wall
                                                                                                               User tips for monitoring temperature




     WITH    • At the centre between the top layer                         • At the centre between
     WHAT      packagings                  • At the centre between the       the layers – insert probe fully
             • Prot.: Incoming goods, meat   layers, insert probe fully    • Prot.: Incoming goods, meat
                                           • Prot.: Incoming goods, meat
     WHO:    • Incoming Goods Acceptance • Incoming Goods Acceptance • Incoming Goods Acceptance
     WHEN    • Immediately on delivery     • Immediately on delivery       • Immediately on delivery
     HOW     • 4 measurements per          • 5 meas. for 2 layers,         • 5 meas. for 2 layers,
     OFTEN    container                     - 2 measurements                - 2 measurements
                                            for every additional layer      for every additional layer
             • Differences < 1 °C          • Differences < 1 °C            • Differences < 1 °C
     VALUE   • Mean value £ 7 °C           • Mean value £ 7 °C             • Mean value £ 7 °C




     WHAT Incoming goods,                  incoming goods
          frozen poultry                   deep-frozen poultry




             • Digital thermometer with • Digital thermometer with
              penetration probe           penetration probe
     HOW/    • Measure on two bodies     • Measure on two bodies
     WITH     per container               per container
     What    • Protocol: Incoming goods, • Protocol: Incoming goods,
              frozen food                 frozen food
     WHO:    • Incoming Goods Acceptance • Incoming Goods Acceptance
     WHEN    • Immediately on delivery     • Immediately on delivery
     HOW     • 2 measurements per          • 2 measurements per
     OFTEN    container                     container
             • Differences < 1 °C          • Differences < 1 °C
     VALUE   • Mean value £ -12 °C         • Mean value £ -18 °C
                                                                                                               User tips for monitoring temperature




67
   68
WHAT Fresh produce,                   Fresh produce,                  Fresh produce,
     delicatessen                     delicatessen                    delicatessen
                                         Recommended                      Recommended
                                         measurement points               measurement points




        Boxes, cases, crates          Boxes, cases, crates            Box, case, crate
        container; single             container; stacked              container; palletized
        • Digital thermometer with    • Digital thermometer with      • Digital thermometer with
          penetration probe             penetration probe               penetration probe
                                                                                                                                         User tips for monitoring temperature




        • At three points along       • At three points along         • At three points at the
HOW/      the outside wall              outside wall on the             top along the outside wall
WITH    • At the centre between the     top layer                     • At the centre between
WHAT      packagings                  • At the centre between the       the layers – insert probe fully
        • Prot.: Incoming goods,        layers – insert probe fully   • Prot.: Incoming goods,
          fresh produce               • Prot.: Incoming goods,           fresh produce
                                        fresh produce
WHO:    • Incoming Goods Acceptance • Incoming Goods Acceptance • Incoming Goods Acceptance
WHEN    • Immediately on delivery     • Immediately on delivery       • Immediately on delivery
HOW   • 4 measurements per            • 5 meas. for 2 layers,         • 5 meas. for 2 layers,
OFTEN container                        – 2 measurements                – 2 measurements
                                       for every additional layer      for every additional layer
        • Differences < 1 °C          • Differences < 1 °C            • Differences < 1 °C
VALUE   • Mean value £ 7 °C           • Mean value £ 7 °C             • Mean value £ 7 °C




WHAT Fresh produce,                   Dry goods                       Dry goods                           Fresh fruit
     mixed and palletized                                                Recommended meas-
                                                                                                          Fresh vegetables
                                        Recommended measure-                                                                    Recom-
                                        ment points                      urement points                                         mended
                                                                                                                                meas.
                                                                                                                                pt.

                                                       Crisps


                                                       Crisps


                                                       Crisps
                                         Crisps




        • Digital thermometer with    Boxes, containers               Boxes, containers
          penetration probe           single and stacked              palletized                          Punnets, containers
        • Check composition            • Digital thermometer with • Digital thermometer with • Digital thermometer
         of goods and separate           penetration probe            penetration probe             penetration probe
HOW/     partial deliveries            • Under lid of top container, • Twice under lids            • In each punnet/
WITH    • Note poss. contamination      measure once between          containers on the top layer, or container per product
WHAT     and penetration of moisture individual layers                measure twice between         measure once at the edge
         and reject if necessary        the individual layers         between fruit/vegetables • Prot.: Incoming goods,
        • Measure individual           • Prot. Incoming goods,       • Prot.: Incoming goods,        fresh produce
         deliveries his order: frozen   fresh produce                  fresh produce
         food, fresh produce, dry food
WHO:    • Incoming Goods Acceptance • Incoming Goods Acceptance • Incoming Goods Acceptance • Incoming Goods Acceptance
WHEN    • Immediately on delivery     • Immediately on delivery       • Immediately on delivery           • Immediately on delivery
HOW     • As per check plan           • 1 measurement per container • 2 measurements per layer            • 1 measurement per
OFTEN     for individual deliveries                                                                        punnet/container
VALUE   • As per check plan           • Differences < 2 °C            • Differences < 2 °C                • Differences < 2 °C
          individual deliveries       • Mean value £ 25 °C            • Mean value £ 25 °C                • Mean value £ 25 °C
                                                                                                                                         User tips for monitoring temperature




   69
70
     WHAT Upright freezer                                                                                           Chest freezer




                                                                                 Upright freezer with drawers       Chest freezer

                                                                                 • Digital thermometer with         • Digital thermometer with
                                                                                  penetration probe                  penetration probe
                                                                                 • Immediately after                • Immediately after
     HOW/                                                                         opening the door along             opening the lid
     WITH                                                                         the outer edge of the door in      along both longitudinal
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   User tips for monitoring temperature




     WHAT                                                                         the closed drawer                  edges at 30 cm intervals
                                                                                  – Insert probe fully              • With lid open, in the centre
                                                                                 • With drawer open, in the          between the frozen food
                                                                                   centre between frozen food        at 30 cm intervals
                                                                                 • Protocol: Freezer                • Protocol: Freezer
     WHO                                                                         • Person responsible for freezer • Person responsible for freezer
     WHEN                                                                        • Every 3 months, not              • Every 3 months, not
                                                                                  immediately after filling          immediately after filling
     HOW   • 2 measurements per                                                                                     • At least 9 measurements
     OFTEN drawer                                                                                                     per chest, 3 further meas-
                                                                                                                      urements at 30 cm intervals
           • Differences £ 4 °C                                                                                     • Differences £ 4 °C
     VALUE • Mean value £ -18 °C                                                                                    • Mean value £ -18 °C
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              9.




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    Date




       Goods rejected
                                                                         Goods accepted
                                                                                                                                                                        Other incoming goods
                                                                                                                                                                                                                                                                                                                                                 Incoming goods, frozen food
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    Time




                                                                                                                                                                                                                                                                                                                                                                                                                      Incoming goods, dairy products
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        cation and commercial use.




                                                                                                                                                                                                                                          Incoming goods, consumer goods
                                                                                                                                                                                                                                                                                                                                                                               Incoming goods, chilled goods, loose


                                                                                                                                                                                                                                                                                                            Incoming goods, dry packaged goods
                                                                                                                                                                                                                                                                                                                                                                                                                                                       Incoming goods, fresh fruit and vegetables
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              Specimen protocols




                                                                                                                                                                                                                                                                                                            Comments:
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    Delivery note no.




                                                                                                       Mean value
                                                                                                                                                                                                                                                                                                                                                 Goods as ordered
                                                                                                                                                                                                                                                                                                                                                                               Quantity as ordered
                                                                                                                                                                                                                                                                                                                                                                                                                      Container intact + clean
                                                                                                                                                                                                                                                                                                                                                                                                                                                       Packaging intact + clean
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        internal use by the company. The authors retain the right of publi-
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        The specimen protocols shown below may be copied by a user for




                                                                                                                      Temperature measurement according to check plan




                                                                         Supplier’s countersignature
                                                                                                                                                                        ...............................................................
                                                                                                                                                                                                                                          ...............................................................
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    Contact person




       ...............................................................
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   Specimen protocols




71
     Specimen protocols                                                                                                                                                                                     Specimen protocols

      Date                   Time                  Contact person                                                                                                            Training report

                                                                                                                            Date                       Time                       Delivery note no.              Contact person

      Supplier               Invoice no.           Delivery note no.



                                                                                                                            Content of training:                                    Reference to documents/material

      Incoming goods, fresh fruit and vegetables         Packaging intact + clean                                             ............................................            ...................................................
      Incoming goods, dairy products                     Container intact + clean                                             ............................................            ...................................................
      Incoming goods, chilled goods, loose               Quantity as ordered                                                  ............................................            ...................................................
      Incoming goods, frozen food                        Goods as ordered                                                     ............................................            ...................................................
      Incoming goods, dry packaged goods                 Comments:
      Incoming goods, consumer goods                     ...............................................................
      Other incoming goods                               ...............................................................                                                      Participants


                          Temperature measurement according to check plan                                                   Name                                                    Signature




                                                          Mean value

      Goods accepted                                     Supplier’s countersignature
      Goods rejected                                     ...............................................................   By signing on completion of the training course, participants affirm that they have taken part
                                                                                                                           in the training and that the content was presented in a way they could understand.




72                                                                                                                                                                                                                                          73
     Notes   Notes




74                   75
                                                                 0980 4353/san/R/Q/01.2007 • Nominal charge EUR 4.00
testo AG
Postfach 1140, 79849 Lenzkirch
Testo-Straße 1, D-79853 Lenzkirch
Tel.: +49 (0) 7653 681-700
Fax: +49 (0) 7653 681-701
info@testo.de
www.testo.de



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can be found at www.testo.com

				
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