ESP Safety SGOES, Руководство по эксплуатации

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SGOES Infrared Combustible Gas Detector
820-0006 Operating Manual
Page 5
Principles of Operation
Operation is based on selective signal disruption by hydrocarbon molecules. An infrared
light source is reflected to a set of optical detectors that simultaneously monitors the
infrared power at multiple wavelengths of the infrared spectrum. If no gas is present, the
photodetectors will receive all of the power radiated by the IR source. When gas
molecules enter the collection chamber the gas selectively absorbs infrared energy at
wavelengths specific to the gas. As a result the detector monitoring the wavelength
specific to the gas records a drop in infrared signal, and the signal from the detector
monitoring a wavelength unaffected by the gas does not change. The ratio of the
photodetector signals, when properly calibrated, provides a quantitative measurement
of the target gas concentration.
Figure 1-1: Hydrocarbon Gas Detection