基于28kHz音叉的光束石英增强光声光谱法实现ppb级气体检测。

Ppb-level gas detection using on-beam quartz-enhanced photoacoustic spectroscopy based on a 28 kHz tuning fork.

作者信息

Lin Haoyang, Zheng Huadan, Montano Baiyang Antonio Zhou, Wu Hongpeng, Giglio Marilena, Sampaolo Angelo, Patimisco Pietro, Zhu Wenguo, Zhong Yongchun, Dong Lei, Kan Ruifeng, Yu Jianhui, Spagnolo Vincenzo

机构信息

Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, and Department of Optoelectronic Engineering, Jinan University, Guangzhou 510632, China.

State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China.

出版信息

Photoacoustics. 2021 Dec 6;25:100321. doi: 10.1016/j.pacs.2021.100321. eCollection 2022 Mar.

DOI:10.1016/j.pacs.2021.100321

PMID:34976726

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC8683655/

Abstract

In this paper, an on-beam quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor based on a custom quartz tuning fork (QTF) acting as a photoacoustic transducer, was realized and tested. The QTF is characterized by a resonance frequency of 28 kHz, ~15% lower than that of a commercially available 32.7 kHz standard QTF. One-dimensional acoustic micro resonator (AmR) was designed and optimized by using stainless-steel capillaries. The 28 kHz QTF and AmRs are assembled in on-beam QEPAS configuration. The AmR geometrical parameters have been optimized in terms of length and internal diameter. The laser beam focus position and the AmR coupling distance were also adjusted to maximize the coupling efficiency. For comparison, QEPAS on-beam configurations based on a standard QTF and on the 28 kHz QTF were compared in terms of HO and CO detection sensitivity. In order to better characterize the performance of the system, HO, CH and CO were detected for a long time and the long-term stability was analyzed by an Allan variance analysis. With the integration time of 1 s, the detection limits for HO, CH and CO are 1.2 ppm, 28.8 ppb and 2.4 ppm, respectively. The detection limits for HO, CH and CO can be further improved to 325 ppb, 10.3 ppb and 318 ppb by increasing the integration time to 521 s, 183 s and 116 s.

摘要

在本文中，实现并测试了一种基于定制石英音叉（QTF）作为光声换能器的光束上石英增强光声光谱（QEPAS）传感器。该QTF的共振频率为28kHz，比市售的32.7kHz标准QTF低约15%。使用不锈钢毛细管设计并优化了一维声学微谐振器（AmR）。28kHz的QTF和AmR以光束上QEPAS配置进行组装。对AmR的几何参数在长度和内径方面进行了优化。还调整了激光束聚焦位置和AmR耦合距离以最大化耦合效率。为作比较，基于标准QTF和28kHz QTF的光束上QEPAS配置在H₂O和CO检测灵敏度方面进行了比较。为了更好地表征系统性能，对H₂O、CH₄和CO进行了长时间检测，并通过艾伦方差分析对长期稳定性进行了分析。积分时间为1s时，H₂O、CH₄和CO的检测限分别为1.2ppm、28.8ppb和2.4ppm。通过将积分时间分别增加到521s、183s和116s，H₂O、CH₄和CO的检测限可进一步提高到325ppb、10.3ppb和318ppb。