Abstract
In the process of methane measurement based on tunable diode laser absorption spectroscopy (TDLAS), the interference fringes generated by the multiple reflections and scatterings of optical surfaces in the optical path make the background signal fluctuate and influence the measurement of low concentration gas. In this paper, a method based on Levenberg-Marquardt (LM) algorithm and TDLAS is proposed to measure low concentration methane. The second harmonic of 95 cm3/m3 methane is firstly selected as reference signal which is taken from a same TDLAS detection system with that of the methane to be measured. Because the influence of interference fringes on both signals is correlated, the gas concentration can be calculated when the measured data is nonlinear fitting by LM algorithm with the reference signal. The results of nonlinear fitting and validation experiments show that the proposed method can significantly reduce the influence of background noise on measurement results, and the accuracy of measurement can be effectively improved. The combination of LM algorithm and TDLAS is an effective method in low concentration methane measurement and can be used to realize the online measurement of low concentration methane.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
