摘要
基于光谱吸收原理,研究了一种长光程下对硫化氢气体进行高灵敏度检测的新方法。为了提高检测精度,应用Herriot光学吸收池,令光在气室中多次往返,获得较长的吸收光程。对该气室进行光路的仿真,模拟光路的反射,得到了20.4 m的光程。采用具有良好波长选择性的分布反馈半导体激光器作为光源,同时对光源进行调制和滤波处理。利用光衰减器设置参考光路,对两光路输出信号进行差分。仿真系统中,选取设置几组硫化氢气体浓度值,得到对应的二次谐波幅值。通过对这几组数值的函数拟合得到测得的浓度值。结果表明设定的硫化氢浓度与反演得到的浓度值呈现出很好的线性关系,通过对比设定浓度值和反演浓度值,结果得出浓度误差始终在0.5%以下。经仿真实验表明,长光程的硫化氢高灵敏度的测量方法提高了测量的精度,且光路的多次反射减小了气室的体积,可大范围应用于气体检测当中。
Based on the principle of spectral absorption,a new method for high sensitivity detection of hydrogen sulfide gas under long optical path is studied.In order to improve the detection accuracy,Herriot optical absorption cell is used.The light is made to travel back and forth in the air chamber multiple times to obtain a longer absorption path.The air chamber is optically simulated,and the reflection of the optical path is simulated to obtain an optical path length of 20.4 meters.A distributed feedback semiconductor laser with good wavelength selectivity is used as a light source,and this light source is modulated and filtered.The optical attenuator is used to set the reference optical path,and the output signals of the two optical paths are differentiated.In the simulation system,several groups of hydrogen sulfide gas concentration values are selected and set to obtain the corresponding second harmonic amplitude.By fitting the functions of these groups of values,the measured concentration values are obtained.The results show that there is a good linear relationship between the concentration of hydrogen sulfide and the concentration value obtained by inversion.By comparing the concentration value set and the inversion concentration value,the concentration error is always less than 0.5%.The simulation experiments show that the high sensitivity measurement method of hydrogen sulfide with long optical path improves the measurement accuracy.And the multiple reflections of the optical path reduce the volume of the gas chamber,which can be widely used in gas detection.
作者
陈书旺
宋彤彤
尹晓伟
CHEN Shuwang;SONG Tongtong;YIN Xiaowei(Institute of Information Science and Engineering,Hebei University of Science and Technology,Shijiazhuang Hebei 050018,China)
出处
《电子器件》
CAS
北大核心
2020年第4期736-740,共5页
Chinese Journal of Electron Devices
基金
国家自然科学基金项目(41474121)
河北科技大学研究生创新项目。
关键词
光谱吸收
硫化氢浓度
光学吸收池
差分
二次谐波
spectral absorption
hydrogen sulfide concentration
optical absorption cell
differential
second harmonic
