Quasi-distributed quartz enhanced photoacoustic spectroscopy sensing based on hollow waveguide micropores

• Weipeng Chen, Shunda Qiao, Ying He, Jie Zhu, Kang Wang, Limin Xiao, and Yufei Ma
• received 03/29/2024; accepted 04/21/2024; posted 04/22/2024; Doc. ID 525188
• Abstract: In this article, a quasi-distributed quartz enhanced photoacoustic spectroscopy (QEPAS) gas sensing based on hollow waveguide micropores (HWGMP) was reported for the first time. Three micropores were developed on the HWG to achieve distributed detection units. Three self-designed quartz tuning fork (QTFs) with low resonant frequency of 8.7 kHz were selected as the acoustic wave traducer to improve the detection performance. Compared with micro-nano fiber evanescent wave (FEW) QEPAS, HWGMP-QEPAS sensor has advantages such as strong anti-interference ability, low loss and cost. Acetylene (C2H2) was selected as the target gas to verify the characteristics of the reported sensor. The experimental results showed that the three QTFs almost had the same sensing ability and possessed an excellent linear concentration response to C2H2. The minimum detection limits (MDL) for the three QTFs were determined as 68.90 ppm, 68.31 ppm, and 66.62 ppm, respectively. Allan deviation analysis indicated that the system had good long-term stability and the MDL can be improved below 3 ppm in an average time of 1000 s.