“…However, precisely characterizing methane fugitive emissions in oil/gas facilities is a demanding measurement technique within conventional pollution monitoring and control strategies [ 11 ]. Laser spectroscopy techniques, such as tunable diode laser absorption spectroscopy (TDLAS) [ 12 , 13 , 14 ], quartz-enhanced photoacoustic spectroscopy (QEPAS) [ 15 , 16 , 17 ], light-induced thermoelastic spectroscopy (LITES) [ 18 , 19 , 20 ], etc., have garnered significant development in the field of trace methane detection in recent years due to their advantages of high sensitivity, precision, and non-contact measurement capabilities. Ye et al presented a highly sensitive methane-detection system based on beat frequency QEPAS technology, which achieves a minimum detectable limit of 28.35 ppm for methane with an integration time of 114 s [ 15 ].…”