Design of the methane concentrations monitoring system based on labVIEW with infrared absorption sensor

According to the relationship between the change of methane concentrations and the light absorption under its characteristics absorption wave, coupled with the analysis of infrared absorption spectrum, this article put forward a kind of methane concentrations detection system design scheme with infrared absorption technology based on differential absorption technique. With a single optical path absorption chamber and dual-wavelength detection technology, the system transmitted the signals to host computer through AD conversion, which are the output of weak signal regulate circuit with the differential amplifying circuit as its core circuit. After FFT transform and digital filtering, the methane concentrations can be obtained from the data. The experiment result shows that this system has high sensitivity and stability in methane concentrations detection, and it has the basis in coal mine application.