摘要
基于二极管激光波长调制光谱技术建立了一套参数主动控制的痕量气体实时在线探测系统。为提高系统的实时在线测量性能和测量精度,在模拟温度与压强对痕量气体浓度探测影响的基础上,待测气体的温度、压强和流量被主动控制,并能保持长期稳定性。小波去噪和卡尔曼滤波数字降噪技术被联合应用于系统。以CO_2分子吸收为例的实验结果表明,小波去噪的应用将吸收光谱的信噪比提高了30%左右,卡尔曼滤波的应用将CO_2体积分数的测量精度由2.5×10^(-7)提高至7×10^(-8)。Allan方差结果给出了系统的稳定时间,约为60s。实测实验室内CO_2浓度的结果表明,该测量系统具有良好的稳定性和可靠性,能够很好地监测痕量气体浓度的变化。
Based on diode laser wavelength modulation spectroscopy technique,a set of real-time and on-line measurement system for trace gases is established with active control parameters.In order to improve the performance of real-time and on-line measurement and the detection precision of the system,after a theoretical simulation of the effects of temperature and pressure on the measurement concentration,we actively control the temperature,pressure and mass flow of gas,and they can keep long-term stability.Moreover,the digitized techniques of wavelet denoising and Kalman filtering are jointly applied to the system.CO2 molecular absorption experimental results show that the signal-to-noise ratio of the absorption spectrum is improved by about 30% with the application of wavelet denoising,and the application of Kalman filter improves the measurement precision of concentration from 2.5×10^-7 to 7×10^-8.The stable time of the system given by Allan variance is about 60 s.The results obtained by measuring the concentration of CO2 in laboratory indicate that the system has good stability and reliability,and it can monitor the concentration change of trace gas very well.
作者
孙明国
马宏亮
刘强
曹振松
王贵师
刘锟
黄印博
高晓明
饶瑞中
Sun Mingguo;Ma Hongliang;Liu Qiang;Cao Zhensong;Wang Guishi;Liu Kun;Huang Yinbo;Gao Xiaoming;Rao Ruizhong(School of Mathematics and Physics, Anhui Polytechnic University, Wuhu, Anhui 241000, China;Key Laboratory of Atmospheric Composition and Optical Radiation, Chinese Academy of Sciences, Hefei, Anhui 230031, China;Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics ＆ Fine Mechanics, Chinese Academy Sciences, Hefei, Anhui 230031, China;School of Physics and Electronic Engineering, Anqing Normal University, Anqing, Anhui 246011, China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2018年第5期336-342,共7页
Acta Optica Sinica
基金
国家重点研发计划(2016YFC0303900,2017YFC0209700)
国家自然科学基金(41405022)
中国科学院青年创新促进会基金(2015264)
安徽省高校自然科学基金(TSKJ2016B12)
关键词
光谱学
激光吸收光谱
二次谐波
痕量气体
浓度反演
spectroscopy
laser absorption spectroscopy
second harmonic
trace gas
concentration retrieve
