MULTIPOINT GAS SENSING APPARATUS

摘要

A modular architecture is implemented in the apparatus providing a multipoint optical gas sensing network. A laser beam from a tunable laser diode source is split and each of the resulting beams is directed via optical fibres to respective gas sensing cells. As the laser beam is configured to sweep a range of frequencies spanning a characteristic absorption frequency of a target gas, a measurement of the level of absorption of the light from the laser beam incident at each cell is correlated with the concentration of the target gas. Photodetectors are arranged to receive light transmitted through the respective cells and the attenuation sensed in the laser beam is attributed to absorption (once other factors have been corrected for). The photodetectors are arranged in groups on receiver modules: receiver modules are provided with dedicated processing capability.