Multiline absorption spectroscopy for methane gas detection.
A multiline absorption spectroscopy technique was investigated based on the single-line absorption spectroscopy technique. An open-path methane-detecting system was designed. An LED was used as a broadband source, and a Fabry-Perot interferometer whose transmission peaks matched the methane R-branch absorption lines was used to enhance the detectable sensitivity. We demonstrate a minimum-detectable concentration of 7600 +/- 10% ppm (parts per million) with a multiline differential absorption spectroscopy technique and a concentration of 1000 +/- 10% ppm with a multiline wavelength modulation spectroscopy technique.
Qu
Yi
Y
College of Physics, Jilin University, Changchun 130023, China.
Kang
Zhi-Hui
ZH
Jiang
Yun
Y
Gao
Jin-Yue
JY