SpectraSensors TDL Analyzer Overview-Process by huanghengdong

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									SpectraSensors, Inc.
Tunable Diode Laser
Analyzer Overview
       Tunable Diode Laser (TDL)
         Spectroscopy History

• TDL was developed and refined by
  NASA at Caltech’s Jet Propulsion
  Laboratory over a 20 year period
• Original systems were developed
  and flown on aircraft and weather
  balloons used for atmospheric
  research
• Achieved space flight qualification
  and launched on the 1999 Mars
  Polar Lander Spacecraft
• Today the technology is considered
  mature and reliable

Product Overview         2
June 8, 2006
               SpectraSensors, Inc.

• SpectraSensors established in
  1999
     – Acquired patent rights to
       commercialize the technology of the
       tunable diode laser
     – Based in San Dimas, California
• First application was ppm levels of            SpectraSensors’ Facility
                                                     San Dimas, CA
  moisture in natural gas streams
     – First unit was sold to El Paso Products
     – Over 1000 units sold since then
• Now offering other process
  applications
Product Overview                 3
June 8, 2006
   But What Are TDL Analyzers?

• Nothing more than fancy Infrared Analyzers* that
  folks are already familiar with
• But rather than using a lamp to produce lR light,
  TDL analyzers use a “focused” and “tunable” laser
  beam
• TDL technology is being driven by the fiber-optic
  telecom industry
• Goal is to retain the simplicity of IR analyzers yet
  avoid some of the measurement issues
  associated with IR analyzers
    * Note that TDL analyzers are available in IR and UV
      ranges depending on laser selected
Product Overview                                 4
June 8, 2006
                   Optical Absorption
                     Spectroscopy

• Absorption of light is
  measured in order to
  determine the concentration
  in the gas sample.
• Light lost is directly and
  principally proportionate to
  absorbance of that light
  source.


           ρ = -ln(T) / k(ν) * L


Product Overview                   5
June 8, 2006
          Measurement Mechanics Of
            Optical Spectroscopy




 Concentration =   (How much light is absorbed (energy) thru the sample cell)
                   (Absorption Coefficient for a species) x (its path length)


Product Overview                     6
June 8, 2006
   On-Line TDL Analyzers Similar To
       Current NDIR Offerings

• Cross Stack design
     – Used to measure components in a combustion process;
       e.g., stack gases
• Open Air design
     – Used to measure components in ambient air monitoring;
       eg, toxic and flammable gases
• Portable design
     – Used to measure components in air or processes; e.g.,
       moisture in natural gas
• Extractive design
     – Used to measure components in chemical processes;
       e.g., gas purity applications


Product Overview               7
June 8, 2006
         Optics Of A TDL Analyzer

     Laser and Detector Head




                    Sample Outlet




Sample Inlet



Product Overview                    8
June 8, 2006
               Tunable Diode Laser




Product Overview        9
June 8, 2006
        Reading The Fine Print Of
          Spectral Signatures



                                     Laser Line



                                        Spectral
                                        Feature




                            1 cm-1




Product Overview    10
June 8, 2006
        Tunable Diode Laser Scan

                                                         Water vapour
              3.0                                        absorption peak
                        Laser Light Spectrum
                        Water Absorption Spectrum

              2.0



              1.0



               0
              1370900           WAVELENGTH (picometer)   1371000


Tunable range 3 nanometers
Scanning 4 times per second
Product Overview                         11
June 8, 2006
                                              Ratio Of Signal At Peak And
                                                          Base
                                      2000
                                                                                              H2O
Detector Response (arbitrary units)




                                      1500



                                      1000




                                       500
                                                                                                                      CH4
                                                                                                          CH4
                                                                   CH4
                                         0                                                                                        CH4


                                       -500


                                                                                    Scan Range
                                      -1000
                                              0   50   100   150     200      250       300         350         400         450         500


                                                                   Laser Current (wavelength)


          By ratioing the measurement against the baseline, errors caused by changes
              in signal strength, cell contamination, dirty mirror, etc are eliminated

                    Product Overview                                          12
                    June 8, 2006
        Analytical Benefits Of TDL
                Analyzers

• Reduced measurement errors due to fewer
  interfering components
• Reduced effects of contamination due to oils and
  other compounds in the stream
• Low measurement ranges with long path samples
  cells (Herriott cells)
• Choice of IR laser sources
• Very fast response times




Product Overview        13
June 8, 2006
                     Extremely Fast Speed of
                           Response
        100000




         10000                                                        95% Response in <10 sec

          1000
  PPM




           100




            10




             1
                 0   5   10   15   20   25   30   35   40   45   50   55   60   65   70   75   80   85
                                                       Minutes




Product Overview                                                 14
June 8, 2006
  Faster Recovery From Process
             Upsets

                           TDL Analyzer


                                                   Other Moisture Sensor
    Concentration of H2O




                                    Time (Hours)
Product Overview                           15
June 8, 2006
        Limitations Of TDL-based
                Analyzers

• Still subject to interferences from very
  complex samples
• Typically limited to low pressure vapor
  samples
• Difficulty measuring compounds heavier
  than C3 in size
• Selection of IR lasers still limited to certain
  spectral ranges (but selection is
  growing!!)

Product Overview       16
June 8, 2006
        SpectraSensors Analyzers

• Compact field-mountable design
     – Div. II and Div I installations
     – NEMA 4 Packaging
• Flexible analytical hardware
     – Choice of IR or UV lasers
     – Single and dual channel
       configurations
     – Multi-pass cells available
• Extremely low cost of ownership
     – No routine maintenance
     – No routine calibration needed
• Fast measurement response                   SS-2000
     – Most applications are done in 1
       second




Product Overview                         17
June 8, 2006
        SpectraSensors Analyzers
                                 Sample
                               Conditioning
                                  Panel




            SS1000




                          SS3000
Product Overview     18
June 8, 2006
          Hardware Specifications

• Safety
     – Div II C,D standard (Optional Div I package available)
     – Gas pressure not to exceed 20 psia in sample cell
• Mounting Environment
     – Ambient Temperature: -20 to 50°C (0 to 122°F)
• Power
     – Choice of 120/220 VAC, 12 Volt DC, 24 Volt DC
• Signals (separate outputs for each channel)
     – 4-20 mA current loop (isolated, current source)
     – Serial data output (RS-232)
     – Digital Outputs (general purpose)




Product Overview               19
June 8, 2006
            Extremely Low Cost Of
                 Ownership
  • No routine maintenance needed
       – No moving parts or user adjusted
         settings
       – No contamination of measurement
         device due to oils other contaminants
       – No consumables                          Laser Head

  • No routine calibration needed                         Pressure Sensor
       – Self compensates for drift, loss of                                        Gas In

         signal, pressure and temperature
         changes
                                                               Temperature Sensor


       – Does this four times a second!              Gas Out
  • If cleaning of mirrors is needed,                                Sample Cell

    typically takes less than 30 minutes
       – Simply unbolt window section and
         wipe with optical quality cleaner
       – No permanent damage to mirrors or
         windows
       – Note: the unit can continue to
         operate without loss of precision
         even when up to 80% of beam is
         blocked!
Product Overview                       20
June 8, 2006
      PC-Based Spectral Viewing
              Software
• Windows-based software
  package
     – Connect directly via Serial
       Port or via remote modem
       link
• Allows viewing operating
  parameters as well as
  detector signals
     – View/Store/Recall all
       operating settings and
       measurement values
     – Helpful for verifying
       performance as well as
       troubleshooting
• Copy included free with
  each system

Product Overview                     21
June 8, 2006
   On-Line Applications For TDL
            Analyzers

• Moisture Analysis
     –   Moisture (and CO2) in natural gas pipelines
     –   Moisture in feed to polymer reactors
     –   Moisture in corrosive streams
     –   Atmospheric moisture measurements
• Other IR Absorbing Components




Product Overview             22
June 8, 2006
              Typical Measurement
                 Performance*
Component                             Minimum Measuring Range
HCl                                  0-10 ppm
HF                                   0-5 ppm
NH3                                  0-10 ppm
CO                                   0-8000 ppm
H2O                                  0-10 ppm
H2S                                  0-300 ppm
CH4                                  0-200 ppm
O2                                   0-2%
HCN                                  0-40 ppm
CO2                                  0-500ppm

* Per meter of optical path length
Product Overview                      23
June 8, 2006
   Moisture And CO2 In Natural Gas
             Application

• Moisture and CO2 are
  important gas quality
  measurements for natural
  gas pipelines
• Typical ranges are:
     – H2O: 4-20 lb/mmscf
     – CO2: 0-10%
• Traditional analyzers subject
  to measurement errors
     – Glycols and amines
     – Measurement drift
• TDL analyzers avoid these
  measurement errors due to
  non-contacting nature of the
  analysis

Product Overview              24
June 8, 2006
     Low Level Moisture In Polymer
       Reactor Feed Application
• Polymer processes, such as
  polyethylene units, require
  monitoring of feed stocks
  for impurities
     – Even ppb levels of
       moisture can damage
       catalyst
• Traditional moisture
  analyzers are slow to
  respond to concentration
  changes and drift over
  time
• Measuring ranges of 0-
  1000 ppb have been
  demonstrated
     – LDL of 100 ppb currently
Product Overview                  25
June 8, 2006
       Other Applications Of High
               Interest

• Chlorine Processes
     – Moisture, O2 and HCl
• Ethylene Oxide Processes
     – Moisture and ETO
• High Purity Bulk Gases
     – Moisture, Ammonia, etc in pure H2, N2, Air,
       CO2, etc.




Product Overview           26
June 8, 2006
      SpectraSensors Customers




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June 8, 2006
                   Summary

• TDL-based analyzers can be a valuable
  new tool for measurement task solutions
• They offer a number of advantages such
  as simple design, fast response and
  reduced interferences with other
  compounds
• But like all analyzers technologies, TDL-
  based analyzers are not a one-size-fits-all
  solution

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June 8, 2006
             Installation Examples




Product Overview       29
June 8, 2006

								
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