基于波长调制光谱技术的多组分气体遥测系统(特邀)  

Remote Sensor System of Multi-component Gas Based on Wavelength Modulation Spectroscopy(Invited)

作　　者：蒋源 郑睿健 续新科 任隆样 赵刚[1,2] 赵延霆 马维光[1,2] JIANG Yuan;ZHENG Ruijian;XU Xinke;REN Longyang;ZHAO Gang;ZHAO Yanting;MA Weiguang(State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Laser Spectroscopy,Shanxi University,Taiyuan 030006,China;Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China)

机构地区：[1]山西大学量子光学与光量子器件国家重点实验室激光光谱研究所,太原030006 [2]山西大学极端光学协同创新中心,太原030006

出　　处：《光子学报》2023年第3期188-197,共10页Acta Photonica Sinica

基　　金：国家自然科学基金(Nos.61875107,61905136,62175139)。

摘　　要：为实现对危化品气体泄漏的实时、远距离、非接触性监测,提高监测效率和精度,研制了一种多组分气体激光遥测系统。基于波长调制光谱技术,利用STM32芯片结合自主设计的驱动电路对激光器进行控制,采用不同的调制频率分别提取甲烷、氨气、乙炔的二次谐波信号,实现混合气体的同步、实时、远距离遥测。采用光强调制幅度归一化的波长调制光谱技术使遥测结果免受回波激光对信号强度的影响。实验测量表明本系统对甲烷、氨气、乙炔的探测下限分别可以达到87 ppm·m、212 ppm·m、12 ppm·m,测量误差小于10%。测量不同距离下的遥测信号,遥测距离至少可达40 m。本系统为激光痕量气体检测研究与应用提供了一种多气体、实时、同步、高灵敏度、远距离、性能稳定的遥测解决方案,能够广泛应用于矿山灾害气体监测预警,危化品场站和运输管网等场合的气体泄漏监测预警。The economic loss and the threat to personal safety caused by the leakage of hazardous chemical gases in natural gas stations,mining,industrial chemicals,manufacturing,gas pipeline transportation and other places are huge.It is extremely necessary to strengthen the real-time monitoring and warning of such hazardous chemical gas leaks.However,traditional detection methods have defects such as slow response,high maintenance cost,low efficiency,the need for close contact sampling and testing,and the inability to monitor in real time.In recent years,tunable diode laser absorption spectroscopy has become a key technology for trace gas detection,with the advantages of fast measurement response and strong wavelength selectivity.In order to realize real-time,long-distance and non-contact monitoring of hazardous chemical gas leakage and to improve monitoring efficiency and accuracy,a multi-component trace gas remote sensing system based on wavelength modulation spectroscopy is proposed.The core of the system is based on STM32 chip combined with a self-designed driver circuit to control the laser,and the second harmonic signals of methane,ammonia and acetylene are extracted separately by using different modulation frequencies to realize simultaneous,real-time and long-distance detection for the mixed gases.We use wavelength modulated spectroscopy with light intensity modulation amplitude normalization to make the remote sensing results free from the influence of the echo laser on the signal intensity.By comparing the direct absorption signal and the second harmonic signal of the gas concentration detected by the system,it is verified that the wavelength modulation technique has a significant noise suppression effect and can greatly improve the detection sensitivity and detection distance.Through calibration experiments,the measurement accuracy and lower detection limits of the system are evaluated.The experiments have shown that the lower detection limits of the system can reach 87 ppm·m,212 ppm·m and 12 ppm·m for metha

关 键 词：光谱学 痕量气体检测 多组分气体 可调谐半导体激光吸收光谱 波长调制光谱技术 气体遥测 

分 类 号：O433.5[机械工程—光学工程]