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Chemgard TM Infrared Gas Monitor. Chemgard Overview. What is Photoacoustic Infrared and how does it compare with other technologies: Review of traditional IR PIR Theory –What happens when light meets sound? Comparison w/ traditional IR Electrochemical Sensors Flame Ionization Detectors
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Chemgard Overview • What is Photoacoustic Infrared and how does it compare with other technologies: • Review of traditional IR • PIR Theory –What happens when light meets sound? • Comparison w/ traditional IR • Electrochemical Sensors • Flame Ionization Detectors • Gas Chromatography • Solid State Sensors • Chemgard Markets & Applications
Photoacoustic Infrared Gas Detection Technology • To better understand the advantages of Photoacoustic Infrared Technology, we will briefly compare it to the older, more commonly used Absorptive Infrared Technology. • How Does It Differ?
Infrared Detection Methodology • Both absorptive and photoacoustic techniques utilize infrared energy of a selective wavelength. • Majority of gases absorb infrared energy of various wavelengths. • The wavelength selected for use in detection is determined by the gas in use and its specific characteristics.
Infrared Technology • Red is representative of a typical gas absorption characteristic. • Yellow is an infrared wavelength used to detect this specific gas.
Absorptive Technique • All absorptive infrared detection methods differ from manufacturer-to-manufacturer. However, the basic principal remains the same. • Sample and Reference measurements must be taken. • The Sample cell is exposed to the gas to be detected. • The Reference cell is either isolated from the gas to be detected or infrared energy outside the absorptive wavelength characteristics of the gas to be detected is used. • The two measurements are compared. If they are equal, the instrument will indicate zero (0).
Absorptive Technique • When the gas to be detected is present, it absorbs some portion of the Sample infrared energy. • The Reference infrared energy is unaffected by the gas to be detected. • The change in ratio of the Sample and Reference detectors is the actual concentration of gas present.
Photoacoustic Infrared Technology • Has been in use since the 1960’S • MSA –10 Years of experience in PIR gas monitors • Has replaced many traditional infrared analyzers as well as other sensing technologies
Advanced Technology Photoacoustic Infrared sensing technology differs from all other available detection techniques on the market. • It has Two distinct advantages: • The ability to sense a leak as low as in the PPB level for some applications. • The ability to operate long periods of time without adjustment or zero drift, a common problem with all other technologies in use today.
Photoacoustic IR Optical Bench • IR source - wire filament emitting multiple wavelengths of light • Chopper (not shown) - used to setup modulation • Optical filters • provide sensitivity and selectivity for a given gas • selected for specific application • Optical block - volume can be changed for specific ranges • Detector-high sensitivity microphone • Solenoid valves - sample inlet and outlet provide seal during photoacoustic gas detection • Heater and thermostat - temperature control critical for low PPM or PPB detection
Photoacoustic Infrared Technology • Sample Gas Enters the Cell…..
Chemgard Applications • Applications include: • CO, CO2, cleaning agents, solvents, heat transfer fluids & many other common industrial chemicals • Photoacoustic Infrared Gas Detection used in: • plastics, paint, automotive, pharmaceutical, semiconductor, rubber & other general chemical industries
Some Chemgard Customers • 3M • Air Products • BASF • Chrysler • Dow Chemical Co • Dupont • GE Plastics • Kimberly Clark • LA Municipal Authority • Miller Brewing • Mitsubishi • Praxair • Toshiba • Walt Disney • Xerox
The Chemgard Advantage • Utilizes Photoacoustic Infrared Gas Detection Technology • Can detect a wide range of industrial compounds • Detection of Percent, PPM or in some cases PPB levels • High Sensitivity and Selectivity to Gas of Interest