A design and testing of a cost-effective distributed optical remote sensing methane system, which will help one to detect gas leaks from multi-coal face in mines simultaneously, is presented. The fundamentals of the remote detection are based on frequency-modulation spectroscopy (FMS) and harmonic detection. By utilizing fiber-optic splitting technique and reference-signal restoring circuit, the remote sensing system is feasible to employ single laser source to get multi-spot measurement in the near infrared region so that the system described here shows sufficient sensibility, considerably increased reliability and marketability over the presently available system. The minimum measurable path-integrated concentration is estimated to be about 423 ppb-m by experimentation.
© 2005 Chinese Optics Letters
(120.1880) Instrumentation, measurement, and metrology : Detection
(120.5820) Instrumentation, measurement, and metrology : Scattering measurements
(280.3420) Remote sensing and sensors : Laser sensors
Wangbao Yin, Weiguang Ma, Lirong Wang, Jianming Zhao, Liantuan Xiao, and Suotang Jia, "Research on the distributed optical remote sensing of methane employing single laser source," Chin. Opt. Lett. 2, 86-88 (2004)