Match Gas Detection Technology to the Hazard
August 25th, 2009
Errant industrial gases pose a dangerous mix of toxic and flammable hazards. To detect these hazards effectively, safety engineers must choose a gas detector that senses and measures the unique attributes of the target gas.
Following is a brief summary of several gas-detection technologies and the gas hazards they best detect:
Electrochemical technology is effective primarily for toxic gas detection. Electrochemical sensors use very low power for operation (i.e., some models are available for intrinsically safe operation). They provide good accuracy and repeatability. Det-Tronics’ GT3000 is the newest toxic gas detector that uses electrochemical technology.
Metal Oxide Semiconductor (MOS) technology is used primarily for toxic gas detection, especially hydrogen sulfide. It can be used in arid conditions where electrochemical cells dry out. The newest MOS sensors are enhanced by nanotechnology to create NTMOS sensors that respond quickly and work well in extreme temperature and humidity conditions.
Catalytic/Combustible Gas Sensors (CGS) are used widely and effectively to detect hydrocarbon and non-hydrocarbon gases such as hydrogen. In time, however, these sensors burn out. Therefore, they require frequent testing and calibration to adjust the gain as the sensor is depleted.
Point Infrared (PIR) technology is highly effective in detecting combustible gases, such as methane or propane, that contain a hydrocarbon molecular bond. In addition to being impervious to poisoning from contaminants, this sensor requires little maintenance and can indicate fault and failure conditions.
Open Path Gas Detection (OPGD), also called Line of Site (LOS), uses the same principle as PIR but can cover a greater distance – the distance between the IR transmitter and receiver can be over 100 meters. These detectors provide a gas measurement in LFL-m, an integrated measurement of gas in the OPGD path. Because the total amount of gas in the path is measured, the detector cannot discriminate between a large cloud of low concentration gas and a small cloud of high concentration gas.
If you have any questions or comments, please contact us at rss@det-tronics.com.
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