基于非色散红外光谱的可调光程痕量气体检测系统  

Adjustable Optical Path Trace Gas Detection System Based on Non-Dispersive Infrared Spectroscopy

作　　者：宋栓军[1] 程彪 张婕 Song Shuanjun;Cheng Biao;Zhang Jie(School of Mechanical&Electrical Engineering,Xi’an Polytechnic University,Xi’an 710048,Shaanxi,China)

机构地区：[1]西安工程大学机电工程学院,陕西西安710048

出　　处：《光学学报》2024年第21期1-10,共10页Acta Optica Sinica

基　　金：国家自然科学基金青年科学基金(61701384);西安市科技计划先进制造业技术攻关项目(21XJZZ0016);陕西省重点研发计划项目(2023-YBGY-349)。

摘　　要：针对红外痕量气体检测系统体积大、检测精度低和最低检测限高等问题,研制了基于非色散红外(NDIR)光谱的可调光程痕量气体检测系统。利用该系统实现了4种痕量气体的高精度检测,设计并制作了可调光程气体吸收池及集成化红外气体传感器的关键部件结构。为达到最佳光程和光能利用率,基于怀特池结构,以主副镜片相对位置最佳为优化目标,借助光学仿真软件进行光路优化,得到不同气体对应的最佳光程及副镜位置。基于最小二乘法构建气体体积分数计算模型,对系统准确性及最低检测限进行实验测试。结果表明,该系统可实现的光程调节范围为1.6~16 m,光程相对误差为±1%,在1×10^(-6)~500×10^(-6)的体积分数范围内,SF_(6)、CH_(4)、CO和CO_(2)的最大检测误差不高于8%,最低检测限分别降低至1.361×10^(-6)、0.487×10^(-6)、0.420×10^(-6)、0.769×10^(-6)。该系统体积小、检测精度高、最低检测限低,可广泛应用于多种红外痕量气体检测。Objective At present,the infrared trace gas detection system has problems such as large size,low detection accuracy,and high minimum detection limit.As a result,certain limitations exist in the application scenarios of factories,mining areas and households which may cause serious life safety problems and huge economic losses.Most of the research on infrared trace gas detection starts from the volume fraction detection model,but it has difficult in research and little influence on the final model building results.Meanwhile,some scholars start from the cavity of the gas absorption cell to study the influence of the absorption cell on the detection of infrared trace gas,but most of the studies are based on increasing the optical path to improve the detection accuracy.However,generally the longer optical path requires larger volume of the absorption cell,which is not convenient for multi-scene utilization,and few scholars design the gas absorption cell by analyzing the optimal optical path of gas.Therefore,we employ an adjustable optical path trace gas detection system based on non-dispersive infrared(NDIR)spectroscopy with sound accuracy and low detection limits.This system can obtain the optimal detection path for different gases,and the different automatic matching paths can achieve high-precision and low-detection limit detection of gas data.Methods Automatic adjustment is mainly achieved for different optical paths.First,according to the concept of optical path product,the optical path for detecting the 1×10^(-6)volume fraction of SF_(6),CH_(4),CO,and CO_(2)gases is obtained by a simple pass-through gas absorption cell(Table 1).Then,based on the NDIR detection principle,the adjustable optical path gas absorption cell is designed by adopting the White cell structure.According to the structure of White cell,it is found that the relative position of the secondary lenses has a great influence on the optical path,and then the adjustment of the optical path is realized by adjusting the relative position of the second

关 键 词：红外痕量气体检测 NDIR光谱技术 可调光程 怀特池 光程自动调节装置 

分 类 号：TH74[机械工程—光学工程]