基于光声光谱技术的氟化氢气体检测仪的研究

Research on Gas Detector for Hydrogen Fluoride Based on Photoacoustic Spectroscopy

环境污染源排放的氟化氢气体具有腐蚀性强,环境危害性大,排放浓度低的特点。为了实现污染源中排放量低,污染严重的氟化氢气体痕量检测,研制了一种基于光声光谱(PAS)检测原理的污染源氟化氢气体检测仪。通过研究氟化氢气体的特征性吸收波段为1.3μm,并采用谐振环的光谱优化技术实现仪器对氟化氢的选择性吸收。同时通过研究品质因子,共振频率,声压大小及共振腔长的关系和光声池材料的选择,完成了光声池的结构设计。实验结果表明,该仪器的光声信号和气体浓度成良好的线性关系,且灵敏度达到0.08μL/L,系统重复性为1.14%,系统稳定性为4%,同时也表明选用耐腐蚀性强的ZnSe玻璃作为光声池材料使得该检测仪具有抗干扰能力强的特点,能广泛应用于环境中气体污染源的监测。

Hydrogen fluoride（HF）from pollution source is a very corrosive gas which does great harm to the environment.Herein,in order to detect the trace gas,a gas detector based on photoacoustic spectroscopy was developed. It is found that the characteristic absorption band of HF gas is 1.3 μm and the selective absorption of HF gas is also realized by introducing the spectroscopic optimization technique of rings resonators. Meanwhile,by studying the quality factor,resonant frequency,sound pressure,resonant cavity and the materials of photoacoustic cell,the photoacoustic cell was successfully designed. The experimental results show that the photoacoustic signal of the detector has a good linear relation with the gas concentration,and the sensitivity reaches 0.08 μL/L while the system repeatability and stability are 1.14% and 4% respectively. Also,the detector displays strong disturbance resistance by choosing zinc selenide（Zn Se）glass with strong corrosion resistance as the material of photoacoustic cells. So this gas detector can be widely applied in monitoring gas pollutants of the environment.