NO快速检测光腔结构设计与光路仿真

Optical path simulation and design of NO rapid detection optical cavity structure

根据NO与臭氧的化学发光反应机理,提出了一种基于化学发光反应检测原理的用于NO气体快速检测的新型圆柱全反射S型光腔结构。该结构以圆柱内壁全反射S型结构为光腔模型,采用圆柱体光源作为光散射元件,将化学发光光线最大效率地汇聚到探测器的感光面,增强了NO浓度测量信号,提高了检测精度。采用光学软件ZEMAX对所提模型进行光路仿真,通过对比分析表明,S型光腔采集光路对化学发光的采集效率为36.6%。通过实验验证,结果表明,在一定浓度范围内NO气体浓度与化学反应发光强度线性相关度为0.999 2,在量程0‰~2.5‰的范围内,检出限为0.001‰。所提模型结构简单,满足国家标准,为尾气在线检测提供了一种实用的设计方案。

According to the chemiluminescence reaction mechanism of nitric oxide and ozone,a new cylindrical total reflection S-type optical cavity design for rapid detection of nitric oxide gas is proposed.The optical cavity model is based on the total reflection S-type structure on the inner wall of the cylinder.Cylindrical light source is used as the light scattering element,so the chemiluminescence light is concentrated on the photosensitive surface of the detector with maximum efficiency,which strengthens the measurement signal of nitric oxide concentration and improves the detection accuracy.Optical software ZEMAX was used to simulate the optical path of the model.The comparative analysis showed that the chemiluminescence collection efficiency of the S-type optical cavity collection path was 36.6%,and is verified by experiments.The experimental results showed that in a certain range of concentration,there is a good linear relationship between the luminescence intensity of the reaction and the concentration of NO gas.The linear correlation was 0.999 2.In the range of 0‰~2.5‰,the detection limit was 0.001‰.The model is simple in structure and meets the national standards.Moreover,it provides a practical idea of design for the on-line exhaust gas detection.