摘要 |
A gas sensor of the type that detects the presence of a specific gas by monitoring the absorption of optical radiation transmitted through a chamber containing a sample of gas under test comprises an optical source for emitting radiation therefrom and a detector sensitive to radiation emitted from the source at opposing ends of a circumferential chamber, having optically reflective surfaces, extending around the periphery of a sensor housing. The optical pathway between the source and detector may include a radial portion as well as a circumferential portion to allow one or other of the source and detector to be located in a central chamber of the sensor housing.
|