MSA 2003 www.msanet.com
Today s Agenda 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 How Does It Differ? To better understand the advantages of Photoacoustic Infrared Technology, we will briefly compare it to the older, more commonly used Absorptive Infrared Technology. Absorptive Infrared Technology Photoacoustic Infrared Technology
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 In this example, infrared sources deliver infrared energy through separate Sample and Reference cells to separate Sample and Reference detectors.
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
Photoacoustic Infrared Gas Detection Advanced Technology Photoacoustic Infrared sensing technology differs from all other available detection techniques on the market. It has 2 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.
Basic PIR Cell Assembly
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 (not shown) - temperature control critical for low PPM or PPB detection
Photoacoustic Infrared Technology Sample gas enters the cell
Toxic Gas Sensors Comparison of Photoacoustic IR and Other Technologies
Electrochemical Sensors Detection of Oxygen, CO & PPM Level & Other Toxics Disadvantages - Short sensor life - High frequency of calibration - Majority of sensors need oxygen Other Considerations - cost/point - cross-sensitivity to other gases
Flame Ionization Detectors PPM Detection of a wide variety Hydrocarbons Disadvantages -Flame hazard - Need for oxygen and hydrogen generation - frequency of calibration - limited dynamic range
Gas Chromatographs Detection & Separation of Hydrocarbons Disadvantages - Slow response - Labor intensive - Flame hazard - Need for oxygen and hydrogen - frequency of calibration - limited dynamic range
Solid State Sensors Detection of PPM Refrigerants and CO Disadvantages - majority of sensors need oxygen - Non-specific detection - accuracy
Chemical Tape Technology PPM or PPB Detection for a variety of toxic gases Disadvantages - Slow response time - High maintenance - Tape replacement - Limited dynamic range
Technology Comparison PIR ABSORP- TIVE IR E CHEM FID GC SOLID STATE TAPE LOW MAINTENANCE FAST RESPONSE ZERO STABILITY LOW PPM DETECTION LONG SENSOR LIFE INFREQUENT CALIBRATION NO O 2 OR SUPPORT GAS NO FLAME HAZARD SPECIFICITY Sensor dependent % LEVEL DETECTION
Gas Detection Comparison PIR ABSORP- TIVE IR E CHEM FID GC SOLID STATE TAPE Halogenated hydrocarbons & refrigerants Carbon Monoxide Carbon Dioxide Alcohols Semiconductor cleaning solvents Gen. Hydrocarbons & fuels NH3 & amines Aromatics ETO Ketones and Esters
Chemgard Applications Applications include CO, CO 2, 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
Brief List 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 erox
The Chemgard Advantage APPLICATION Multipoint detection of CO and low Oxygen levels in blanketing application TRADITIONAL SOLUTION Combination of separate oxygen E-chem, high end IR sensor and sequencer in a system NEW SOLUTION Multipoint CO Photoacoustic IR detector with integrated oxygen sensor
The Chemgard Advantage APPLICATION Low PPM detection of CO2 in natural gas TRADITIONAL SOLUTION On-line GC Sampling NEW SOLUTION In-stream 0-10 ppm Photoacoustic IR detector for CO2
The Chemgard Advantage APPLICATION Detection of low ppm semiconductor cleaning solvent in a rack with other detection and data acquisition units TRADITIONAL SOLUTION GC packaged in with other units NEW SOLUTION Rack-mount Photoacoustic IR detector for 0-100 ppm detection
The Chemgard Advantage APPLICATION Hydrocarbon Bed Breakthrough Detection of LEL Hydrocarbons TRADITIONAL SOLUTION Flame Ionization Detector NEW SOLUTION P Photoacoustic IR detector with SS Plumbed System
Chemgard Industries Pharmaceutical Semiconductor Petrochemical Rubber Plastics/Paint Agricultural Medical Automotive
Petrochemical Industries Gasoline Diesel Fuel Jet Fuels Methane Ethane Propane Butane Pentane Hexane Benzene Toluene ylene CO 2 Ethylene Oxide Isobutane
Plastics/Paint Industry Chloroform Ethyl Acetate Ethanol Isopropanol Methanol MEK MIBK Methyl Methacrylate Methylene Chloride N-Butanol N-Hexane N-Pentane PF5050 PGMEA Propanal Solkane 365 THF Toluene Trichloroethane Trichloroethylene Vinyl Chloride Vinyl Fluoride ylenes
Agricultural Industries Carbon Tetrachloride Chloroform Dimethylamine Ethyl Acetate Ethylene Ethylene Oxide Methyl Formate N-Hexane N-Pentane Phosgene Trichloroethane
Rubber Industry Acrylonitrile 1,3 Butadiene Styrene Acetone Benzene Carbon Tetrachloride Dimethylamine Ethyl Benzene Ethylene Isobutane Propanal Propylene Oxide Toluene Triethylamine ylenes
Medical & Pharmaceutical Industry Carbon Dioxide Chloroform Diethyl Ether Dimethyl Amine Ethanol Ethylene Oxide Ethylene Heptane Isopropanol Nitrous Oxide Toluene
Semiconductor Industry Carbon Tetrachloride CO Ethanol Hexafluoro 1,3 Butadiene HFE 347E HFE-7100 HFE 7200 Isopropanol Methyl Fluoride Nitrogen Trifluoride Nitrous Oxide Octafluorocyclobutane Octaflurocyclopentene R-32 Sulfur Hexafluoride
Automotive Industry Cyclopentane 1,2 Dichloroethane Dowtherm J Ethanol HFE 7100 HFE 7200 HFE 347E CO
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