Optical Gas Imaging is an effective tool in detecting fugitive emissions at an industrial site. The technique is used to detect leaks of hazardous gasses such as hydrogen sulfide, carbon monoxide and methane. It can also be used to monitor the concentration of other gasses such as oxygen or nitrogen.
The principle behind optical gas imaging is that a light source illuminates the area being monitored and the resulting scattered radiation is detected by a detector. The intensity of the scattered radiation depends on the concentration of the target gas in the illuminated region.
There are two basic types of optical gas detection systems: those which use an array of detectors to measure the total energy of the scattered radiation, and those which employ a single detector for each pixel or cell of the image. In the latter case, the signal from the detector is integrated over time, typically using a charge-coupled device (CCD) or complementary metal oxide semiconductor (CMOS) sensor. This allows the system to operate continuously without requiring any mechanical scanning movements.