J4 ›› 2014, Vol. 27 ›› Issue (1): 16-21.doi: 10.3976/j.issn.1002-4026.2014.01.003

• Oceanographic Science, Technology and Equipment • Previous Articles     Next Articles

TDLAS first harmonic based methane concentration detection system and its temperature compensation

 ZHANG Ke-Ke, QI Yong, FU Xiao, MIAO Bin, BAI Xue-Jiao   

  1. Shandong Provincial Key Laboratory of Ocean Enviromental Monitoring Technology, Institute of
    Oceanographic Instrumentation, Shandong Academy of Sciences, Qingdao 266001, China
  • Received:2013-07-30 Published:2014-02-20 Online:2014-02-20

Abstract:

We analyze the impact of temperature variation on the spectral characteristics of methane absorption line and the concentration measurement of methane gas with the absorption lines in R3 transitions of 2v3 band of methane at 1 653.72 nm. We detect methane gas concentration with first harmonic signal based on tunable diode laser absorption spectroscopy and wavelength modulation spectroscopy. We also suppress the interference of temperature variation on detection accuracy by temperature compensation. Experimental results show that the methane detection system is stable. Its system measurement error is within 1% after the calibration of temperature compensation coefficient, so its system detection accuracy can be effectively improved.

Key words: tunable diode laser absorption spectroscopy, wavelength modulation, first harmonic, temperature compensation

CLC Number: 

  • TN247

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