| 摘要 |
The present invention relates to the infrared detection of hydrocarbon gases; infrared light from a source (10) is passed through a filter (12) to produce a beam (14) passing through a space (16), which can potentially contain hydrocarbon gases. The wavelength of the beam (14) contains a wavelength that is absorbed by hydrocarbon gases (sample wavelength) and a wavelength that is not absorbed by hydrocarbon gases (reference wavelength). The beam (14) falls on a detector that contains sensors (22, 24) that receive light that has passed through respective filters (18, 20). Sample filter (20) allows a single wavelength to be transmitted; reference filter (18) allows two wavelength bands to be transmitted, the bands having wavelengths located on either side of the sample wavelength in order to eliminate the effects of atmospheric conditions that are unconnected with hydrocarbon gases. |
