基于跨波长调制和直接吸收光谱的宽量程多气体检测方法  

Wide-range multi-gas detection method based on wavelength modulation spectroscopy and direct absorption spectroscopy

作　　者：赵晓虎 孙鹏帅[1] 张志荣 王前进 庞涛 孙苗 庄飞宇 Zhao Xiaohu;Sun Pengshuai;Zhang Zhirong;Wang Qianjin;Pang Tao;Sun Miao;Zhuang Feiyu(Anhui Provincial Key Laboratory of Photonic Devices and Material,Anhui Institute of Optics and Fine Mechanics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China;Science Island Branch,Graduate School,University of Science and Technology of China,Hefei 230026,China;Anhui Province Key Laboratory of Simulation and Design for Electronic Information System,Hefei Normal University,Hefei 230601 China;School of Environment Science and Optoelectronic Technology,University of Science and Technology of China,Hefei 230026,China;Key Lab of Environmental Optics&Technology,Anhui Institute of Optics and Fine Mechanics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China)

机构地区：[1]中国科学院合肥物质科学研究院安徽光学精密机械研究所,光子器件与材料安徽省重点实验室,安徽合肥230031 [2]中国科学技术大学研究生院科学岛分院,安徽合肥230026 [3]合肥师范学院电子信息系统仿真设计安徽省重点实验室,安徽合肥230601 [4]中国科学技术大学环境科学与光电技术学院,安徽合肥230026 [5]中国科学院合肥物质科学研究院安徽光学精密机械研究所,中国科学院环境光学与技术重点实验室,安徽合肥230031

出　　处：《红外与激光工程》2023年第1期82-91,共10页Infrared and Laser Engineering

基　　金：国家自然科学基金(42005107,11874364,41877311);国家重点研发计划(2021YFB3201904);安徽省重点研究与开发计划项目(201904c03020005);中国科学院合肥研究院“火花”基金项目(YZJJ2020QN8);安徽省高校自然科学研究重点项目(KJ2019A0722,KJ2021A0909);电子信息系统仿真设计安徽省重点实验室重点项目(2020ZDSYSZD03)。

摘　　要：针对可调谐半导体激光吸收光谱技术(Tunable Diode Laser Absorption Spectroscopy,TDLAS)在煤矿、石油化工领域进行气体浓度检测时,遇到的高精度、宽动态范围需求,采用时分复用的方法,将直接吸收光谱技术(Direct Absorption Spectroscopy,DAS)和波长调制光谱(Wavelength Modulation Spectroscopy,WMS)技术的优势相结合,完成了高精度、宽量程和免标定多气体检测系统的设计。设计激光器的驱动为线性扫描输出和叠加不同高频调制扫描输出的周期信号,用于完成高低浓度反演算法的时分复用计算,通过实验优化选择检测气体的吸光度拐点,实现对气体浓度的高精度、宽量程检测。在室温和常压下,通过实验分别对CH_(4)、CO和C_(2)H_(2)三种气体体积浓度进行检测,确定了两种算法最佳拐点吸光度约为0.026 cm^(-1)。系统对CH_(4)、CO和C_(2)H_(2)三种气体体积浓度的检测量程分别为0~100%、0~5 000×10^(-6)和0~1 000×10^(-6),其最小体积浓度检测限分别为2.27×10^(-4)、0.21×10^(-6)、1.68×10^(-6),且在量程内的测量结果准确度优于现行的煤矿行业标准。实验结果表明:该方法能够满足工业现场实际应用的需求,有利于拓展激光吸收光谱技术在工业过程、安全等领域的应用。When tunable diode laser absorption spectroscopy (TDLAS) is applied to the field of coal mine and petrochemical industry for gas concentration detection,it often needs to meet the requirements of high precision and wide dynamic range.Therefore,we use the time-division multiplexing method to combine the advantages of direct absorption spectroscopy (DAS) and wavelength modulation spectroscopy (WMS) technology to complete a high-precision wide-range calibration-free multi-gas detection system.The driving signal of the laser is designed as a periodic signal,which has linear scanning output signal superimposed with different high-frequency sin-wave modulation.It is used to complete the simultaneous calculation of low and high concentration inversion algorithms by time division multiplexing technology.Moreover,by optimizing the absorbance inflection point of the detected gas,the high-precision and wide-range detection of the gas concentration is realized.Under room temperature and pressure,the concentrations of CH_(4),CO and C_(2)H_(2) are detected by experiments,and the absorbance at the optimal inflection point of the two algorithms is determined to be about 0.026 cm^(-1).The detection range of the system for the concentration of CH_(4),CO and C_(2)H_(2) are 0-100%,0-5 000×10^(-6) and 0-1 000×10^(-6),respectively.And also,the minimum concentration detection limits are 2.27×10^(-4),0.21×10^(-6),and1.68×10^(-6).The above analysis also shows that the system meets the requirements of wide dynamic range and the accuracy is better than the current coal mine industry standard in the whole range.Moreover,this method can meet the needs of various industrial field applications,and is conducive to promoting the application of laser absorption spectroscopy in industrial processes,security and other fields.

关 键 词：可调谐半导体激光吸收光谱技术 直接吸收光谱 波长调制光谱 宽动态范围 

分 类 号：O443.4[理学—电磁学] TN247[理学—物理]