基于石英增强光声光谱技术的开放光路气体传感系统研究

针对传统石英增强光声光谱系统存在体积大、实时性差，无法实现在狭小空间中探测等缺点，提出一种基于光纤引导方式的开放光路石英增强光声光谱传感系统。系统用光纤将激光引导至石英音叉两叉指中央，以实现对狭小空间中痕量气体的探测。搭建了实验系统，开展了对常温常压下空气中水蒸气含量的探测来验证该系统的探测灵敏度及可靠性。得到其归一化噪声系数为7.15e-7cm^(-1)?W/Hz^(1/2)。实验结果表明，该系统的探测灵敏度是传统石英增强光声光谱系统的5倍。该系统体积小、实时性强，无需样本取样，适用于开放环境中对痕量气体的检测。

An Open Path Trace Gas Detection Sensor System Based on Quartz Enhanced Photoacoustic Spectroscopy

To overcome these disadvantages including large volume, low real time and inability to detect trace gas in narrow space in the conventional quartz enhanced photoacoustic spectroscopy (QEPAS) system, a trace gas detection sensor system based on fiber lead open path QEPAS is investigated. The laser source is led to the central of two pins of the tuning fork (TF) by a fiber to realize the detection in narrow space. The experiment for detection of water vapour in the open environment was carried on to evaluate the performance of the system. The experiment results demonstrated that this new led method can reduce energy loss and enhance the detect sensitivity; A normalized noise equivalent absorption coefficient 7.15e-7cm^(-1)?W/Hz^(1/2) is achieved, which is about 5 times higher than of conventional focus mode. The system has a small size, hard real-time, without sample sampling. Applied to the detection of trace gases in the open environment.