大气污染物SO_2的光声探测  

Detection of Air Pollutant SO_2 by Laser-induced Photoacoustic Technique

作　　者：张贵银[1] 张连水[1] 韩晓峰[1] 

机构地区：[1]河北大学物理科学与技术学院

出　　处：《光电子．激光》2005年第7期830-833,共4页Journal of Optoelectronics·Laser

基　　金：河北省自然科学基金资助项目(102090)

摘　　要：以波长为266nm的激光为激发光源,采用脉冲光声光谱技术,用自制的光声探测装置对SO2分子的光声吸收特性进行了实验研究,获得了室温、665Pa气压的实验条件下声音在SO2气体中的传播速度。通过测量光声信号随实验条件的变化发现,光声信号强度随激光能量的增加而增大,随缓冲气体压强升高而增大,缓冲气压增加到约2.66×104Pa时出现饱和现象。在标准大气压情况下,测量了痕量SO2气体的浓度,采用这套光声探测装置,SO2气体探测灵敏度可以达到9.1×10-6。SO2 is one of the major air pollutants. The absorption property of this molecule was tentatively surveyed with the technique of photoacoustic (PA) and with laser radiation of 266 nm as excitation source. The velocity of the sound in SO2 gas was measured under the conditions of room temperature and 665 Pa gas pressure. The intensity of PA signal is correlated with the experimental conditions. It shows that the PA signal is enhanced with both of the laser energy and buffer gas pressure. Optical-acoustic signals appear saturation when the buffer gas pressure is increased to about 2.66 × 104 Pa. Trace concentrations of SO2 are detected under ambient conditions with this technique. The limit of detection of 9.1 ppm is obtained for SO2 in air.

关 键 词：光声光谱技术 SO2分子 声速 探测灵敏度 

分 类 号：O433.5[机械工程—光学工程]