Signal correction using transmitted spot information: A low error photoacoustic spectroscopy-based gas detection system

Photoacoustic spectroscopy (PAS)-based gas sensing system is popular in industries due to advantages of high sensitivity and portable. However, data fluctuation often occurs in the on-line monitoring mode, and the reason has not been found yet. In this work, influential factors and environment-related variables of the photoacoustic (PA) signal were analyzed. A beam quality analyzer was employed as a tool to detect the parameters of the optical path condition. The robustness was verified by a long-time measurement. The results showed that the centroid y of the beam spot has the best linear correlation with the PA signal with a correlation coefficient higher than 0.9. The largest and average measurement error were 26.98 % and 10.95 % without the correction, while after the correction they were only 12.24 % and 5.39 %. The results can provide ideas to the robustness improvement of the PAS gas detection system. [Display omitted] •Influential factors of the PA signal were proposed.•Parameters of the traverse light beam were measured for signal correction.•Relationship between the PA signal and beam parameters were analyzed.•The measurement error of the PAS gas sensing system had been reduced.