基于可调谐半导体激光吸收光谱的氧气浓度测量研究  

Measurement of Oxygen Concentration Using Tunable Diode Laser Absorption Spectroscopy

作　　者：高彦伟[1] 张玉钧[1] 陈东[2] 何莹[1] 尤坤[1] 陈晨[1] 刘文清[1] 

机构地区：[1]中国科学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 [2]合肥工业大学仪器科学与光电工程学院,安徽合肥230009

出　　处：《光学学报》2016年第3期267-273,共7页Acta Optica Sinica

基　　金：国家重大科学仪器设备开发专项(2012YQ22011902);国家高技术研究发展计划(2014AA06A503)

摘　　要：采用可调谐半导体激光吸收光谱(TDLAS)技术,利用氧气在760 nm波段的吸收谱线对氧气浓度进行实时在线测量。研制了基于TDLAS直接吸收技术的氧气检测系统,采用压控放大器设计了自动增益控制模块,实现了对光谱信号幅度的精确控制,解决了现场测量中信号幅度波动的问题;采用归一化洛伦兹函数实现Voigt函数的近似计算,并结合Levenberg-Marquardt非线性拟合算法实现了对光谱吸光度曲线的快速Voigt线型拟合,以适应实时在线检测需要。实验结果表明,该算法可以实现吸光度曲线的Voigt线型拟合,对固定浓度的氧气进行连续测量得到系统的最低检测限为523×10^(-6)m,系统的标准偏差为1.75%。检测系统稳定可靠,满足实时在线氧气浓度检测应用。The tunable diode laser absorption spectroscopy （TDLAS） technology and oxygen absorption lines near 760 nm are used to realize real-time on-line measurement of oxygen concentration. A detection system based on TDLAS direct absorption technique is designed. In order to solve signal amplitude fluctuation for on- site measurement, an automatic gain control module is designed using voltage controlled amplifier to achieve precise control of the spectrum signal amplitude; generalized Lorentz function is adopted to realize the approximate calculation of Voigt function combining Levenberg-Marquardt nonlinear fitting method to realize fast Voigt profile fitting of the absorbance spectrum curve, to meet the requirement of real-time on-line detection. Experimental results show that the algorithm can achieve Voigt profile fitting of absorbance curve. A fixed concentration of oxygen is continuously measured. Minimum detection limit of the system is 523 × 10-6 m, and standard deviation is 1.75%. Detection system is reliable and meets the real-time on-line oxygen concentration detection applications.

关 键 词：光谱学 可调谐半导体激光吸收光谱 自动增益控制 Levenberg—Marquardt非线性拟合 氧气浓度测量 

分 类 号：O657.3[理学—分析化学]