GAS DETECTOR

摘要

A gas detector (10) that is arranged to sense the concentration levels of target gases oxygen, methane, carbon monoxide, and hydrogen sulphide, within a gas sample from an 5 environment surrounding the detector. The gas detector (10) comprises laser sources (12a 12d) that are arranged to transmit radiation through the gas sample at four target wavelengths that correspond approximately to the optimum absorption wavelengths of each of the target gases and an optical detector (16) that is arranged to sense the intensity of the radiation transmitted through the gas sample at each of the target wavelengths. A 10 control system (22) generates representative concentration level information for the target gases based on the level of absorption of the radiation transmitted. 23a 10 23b r uG Laser diode driver 22 18a 18d 22 18b 18c 22 22 24a 2 22 TC1 TC2 TC3 TC4 L1 LD2 LD3 LD4 12a 24b-24c 24d 12b 12c 12d Optical system (cavity) Analog LIA 20 uC|