Enhancement of Methane Detection in Tunable Diode Laser Absorption Spectroscopy Using Savitzky-Golay Filtering

In order to enhance gas absorption efficiency and improve the detection sensitivity of methane, a gas absorption cell with an effective optical path length of 29.37 m was developed, employing tunable diode laser absorption spectroscopy (TDLAS) and a distributed feedback (DFB) laser with a center wavelength of 1.654 mu m as the light source. However, despite these advancements, the detection accuracy was still limited by potential signal interference and noise. To address these challenges, the Savitzky-Golay (S-G) filtering technique was implemented to optimize the TDLAS detection signal. Experimental results indicated a significant enhancement in detection performance. For a methane concentration of 92 ppm, the application of the S-G filter improved the signal-to-noise ratio by a factor of 1.84, resulting in a final device detection accuracy of 0.53 ppm. This improvement demonstrates the effectiveness of the S-G filter in enhancing detection sensitivity, supporting high-precision methane monitoring for atmospheric analysis and various industrial applications.