“…Therefore, the accurate measurement of methane concentration is of great importance for industrial production and environmental protection. , At present, the mainstream methane gas detection technologies mainly include catalytic combustion, electrochemical, thermal conductivity, and gas spectroscopy-based detection technologies. , Spectroscopic detection techniques are becoming increasingly popular among researchers because of their fast response, high selectivity, high sensitivity, and noninvasive real-time measurements . Laser spectroscopy techniques include tunable diode laser absorption spectroscopy (TDLAS), cavity decay spectroscopy (CRDS), photoacoustic spectroscopy (PAS), etc. After obtaining the spectra of the target molecules, the concentrations can be directly calculated by linear or nonlinear fitting of the spectra .…”