GAS LEAK DETECTING DEVICE

摘要

PURPOSE:To easily perform detection over a wide range by detecting gas by using laser light. CONSTITUTION:The laser light 6 from a laser light source 5 passes through a half-mirror 7 and a lens 9 and then passes through a detection area A and is reflected by a reflecting mirror 2. The reflected laser light passes through the area A again and is incident on a photodetecting element 11 through a lens 10. Part of the laser light split by the half-mirror 7 is made incident on a 2nd photodetecting element 18. The wavelength of the laser light is set to wavelength with which the laser light is absorbed by gas to be detected. If the gas leaks and is present in the detection area A, the laser light is absorbed, so the output of the photodetecting element 1 decreases. The ration of the output of the photodetecting element 1 and the output of the photodetecting element 2 is compared with a set value to detect the presence of the gas in the area A.