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ECE5320 Mechatronics Infrared Emission Thermometers by q101dl

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									       ECE5320 Mechatronics

    Infrared Emission Thermometers

               Prepared by:
             Augusto Rodríguez

Dept. of Electrical and Computer Engineering
             Utah State University
           deleon.augusto@gmail.com; (435) 213-1185


                        3/6/2009
                                          Slide-2



                                   Outline
       –    Reference list
       –    To explore further
       –    Major applications
       –    Basic working principle illustrated
       –    A typical sample configuration in application
            (application notes)
       –    Major specifications
       –    Limitations
       –    How to choose an IR thermometer
       –    Cost

5/20/2012           ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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                          Reference list

      • [1]Mechatronics Handbook, The. Robert H. Bishop.
      • [2]Measurement, Instrumentation and Sensors Handbook, The.
        John G. Webster.
      • [3]Use Of Infrared Emission Detection Thermometer. The
        Hong Kong College of Family Physicians.
      • [4]http://www.pyrometer.com/processheating.html
      • [5] http://www.evergreenengineering.com




5/20/2012           ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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                        To explore further
  • The Accuracy of Oral Predictive and Infrared Emission Detection
    Tympanic Thermometers in an Emergency Department Setting.
     – http://www3.interscience.wiley.com/cgi-
        bin/fulltext/119827218/PDFSTART
  • Infrared thermometer with automatic calibration.
     – http://www.google.com/patents?hl=en&lr=&vid=USPAT4784149&id=hEE
        vAAAAEBAJ&oi=fnd&dq=infrared+emission+thermometers.
  • Sensitivity of simple infrared thermometers.
     – http://www.iop.org/EJ/article/0022-3735/16/7/012/jev16i7p613.pdf?request-
        id=d0aa9b0e-c47a-4d7e-9be4-39f8d5106dd1




5/20/2012             ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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                             Major applications
  • Temperature measurement of
    semiconductor materials during
    fabrication process.
       – Sometimes it is necessary to coat the
         semiconductor with a high emissive
         material due to the low emissivity of the
         semiconductor.




              Wafer, semiconductor[5]

5/20/2012                     ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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                           Major applications
    • Medical applications:
            – Skin temperature measurement.
            – Body temperature measurement. Sometimes, this is measured by getting the
              tympanic membrance temperature.
    • Detecting clouds for remote telescope operation.
    • Checking mechanical equipment or electrical circuit breaker boxes or outlets
      for hot spots.
    • Checking heater or oven temperature, for calibration and control purposes
    • Detecting hot spots / performing diagnostics in electrical circuit board
      manufacturing
    • Checking for hot spots in fire fighting situations
    • Monitoring materials in process of heating and cooling, for research and
      development or manufacturing quality control situations


5/20/2012                  ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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             Basic Working Principle

       • IR emission thermomethers are classifiead as
         non-contact thermometers since they don’t
         need to be in contact with the object being
         monitored.
       • These sensors work based on the infrared
         emissions from the object being measured.



5/20/2012        ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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                 Basic Working Principle
  • IR Emission Thermometers work based on the principle that all
    objects whose temperature is above the absolute zero radiate
    electromagnetic waves whose spectrum is associated to its
    surface temperature.
  • Ideally, an IR thermometer consist of a sensor and a detector.
     – The sensor monitors the temperature of a detector.
     – The detector gets the radiative heat transfer of the object’s
       surface.
  • However, the detector has loss and its range of sensing is not
    restricted to the object being measured.
       – Optical devices are used to limit the range of the detector to the object
         being measured.
5/20/2012               ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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                 Basic Working Principle
        The operating principle of the IR thermometer is based
        on Stefan-Boltzmann law:




            Where:
            •Tc is the object’s temperature in Kelvin.
            •    is the net thermal radiation flux.
            •Ts is the sensor’s surface temperature
            • :Emissivity of the object.

5/20/2012             ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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            Basic Working Principle




                              Simple diagram of IR a thermometer [4].



5/20/2012     ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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            A typical sample configuration
  • Measuring the temperature of a semiconductor
    material during fabrication.




                  Diffused-light thermometer for measuring temperature of GaAs wafers [2].




5/20/2012      ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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                 Major Specifications
  • Response time:
       – IR thermometers’ response time is
         around one second, which is
         relatively fast. However, their
         warm up time is relatively large.




5/20/2012          ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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                 Major Specifications
  • Electromagnetic Spectrum: the infrared thermometers
    measure the temperature in the range of 0.7 to 80 µm.




                                      IR Spectrum [4].


5/20/2012          ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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                      Major Specifications
            •   Materials used.




                                                                              [2]




5/20/2012               ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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                   Major Specifications
  • Temperature error:
        – Uncertainties in the
          emissivity of the object
          to measure may result in
          errors in the measured
          temperature.




5/20/2012            ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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                          Limitations
  • There is a limited variety of lenses an filter that
    can be choosen to build IR Emission
    Termometers.
  • IR refractive materials have high absorption of
    light. Thus, there is a limitation with lenses since
    they need to be relatively thick.




5/20/2012       ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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    How to choose an IR Emission Thermometer
  • Several factors have to be taken into account
    before selecting an IR termometer:
       –    Distance to object.
       –    Target temperature range.
       –    Object’s material.
       –    Object’s size.
       –    Ambient temperature.
       –    Gases that might be interfering.


5/20/2012             ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
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                                         Cost
                                            • Depending on the added
                                              features and manufacturer,
                                              cost may vary from USD
                                              $2, 000 to USD $50.00



       They can be easely bought
       online.




5/20/2012             ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

								
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