title: [Design of non-dispersed infrared (NDIR) methane gas sensor].
abstract: A non-dispersed infrared (NDIR) methane gas sensors system based on infrared absorption spectrum theory was designed according to single light beam and double wavelengths technology. In the system, an infrared LED IRL715 serving as the light power, a absorptive gas cell with the function of dust-proof and damp-proof and a pyroelectric detector LIM-262 are composed of optical probe. Signal condition uses active filter circuit and differential amplifier, and binomial expression fits the relation curve between methane concentration and voltage, which realizes accurate detection of gas concentration. Experiment approved that the sensor system with good consistency and applicability can detect the range of 5% methane reliably and have 0.5% of the sensitivity, possessing the conditions for industrial applications initially.
authors.affiliation: Engineering Technology Research Center of Shanxi Province for Opto-Electronic Information and Instrument, North University of China, Taiyuan 030051, China. sbk@nuc.edu.cn
authors.forename: Zheng-Jie
authors.initials: ZJ
authors.lastname: Zhao
authors.forename: Dong-Xu
authors.initials: DX
authors.lastname: Liu
authors.forename: Ji-Long
authors.initials: JL
authors.lastname: Zhang
authors.forename: Zhi-Bin
authors.initials: ZB
authors.lastname: Wang
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
authors.forename: Er-Ming
authors.initials: EM
authors.lastname: Tian