基于光声光谱技术的NO,NO_2气体分析仪研究  

Gas measurement system of NO and NO_2 based on photoacoustic spectroscopy

作　　者：许雪梅[1] 李奔荣[1] 杨兵初[1] 蒋礼[1] 尹林子[1] 丁一鹏[1] 曹粲[1] 

机构地区：[1]中南大学物理与电子学院,长沙410083

出　　处：《物理学报》2013年第20期121-127,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61172047;61071025)资助的课题~~

摘　　要：NO,NO2是大气污染源中的常见气体,对环境具有严重的危害性.为检测污染源中这两种气体的浓度,构建了成本较低的基于红外热辐射光源的光声光谱气体检测系统.分析计算得到了NO,NO2在2500—6667 nm波段吸收谱线.通过建立光声传输线RLC振荡电路模型和仿真得到品质因数、声压大小与谐振腔长、内腔半径以及调制频率的关系,据此设计了光声池几何结构.实验表明该系统所测得的光声信号与气体浓度有很好的线性关系,并且对NO,NO2气体极限检测灵敏度分别达到4.01和1.07μL.通过调节激光发射波长和选取滤波片,该系统还可用于其他微量气体的浓度检测.NO and NO2 are the common gases and have serious harmfulness to the atmosphere pollution of environment. To detect the concentration of the two gases in pollution, we construct a low cost photoacoustic spectrum gas measurement system based on the thermal radiation light source. Absorption lines of the NO and NO2 between 2500 and 6667 nm are calculated. By modeling the photoacoustic transmission line the relations between quality factor, acoustic pressure and cavity length, cavity radius, modulation frequency are obtained, and the design of geometric construction of photoacoustic cell is also guided. The experiment show that there exists a good linearity between photoacoutic signal detected in the system and gas concentration, and the system ultimate detection sensitivities to the NO and NO2 are 4.01 and 1.07 μL/L respectively. When the emission wavelength of laser is regulated suitably and the edmund optics is chosen reasonably, this system is also suitable for the concentration-detection of other trace gas.

关 键 词：大气污染 光声光谱 气体检测 

分 类 号：O657.3[理学—分析化学] X831[理学—化学]