用于涡动相关法的激光气体分析仪的研制  

Development of Laser Gas Analyzer for Eddy Correlation Method

作　　者：李明星 许振宇 阚瑞峰[1] 何亚柏 姚路 陈兵 阮俊 陶邦一 刘浩 Li Mingxing;Xu Zhenyu;Kan Ruifeng;He Yabai;Yao Lu;Chen Bing;Ruan Jun;Tao Bangyi;Liu Hao(Anhui Institute of Optics and Fine Mechanics,Hefei Institutes of Physical Sciences,Chinese Academy of Sciences,Hefei,Anhui 230031,China;University of Science and Technology of China,Hefei,Anhrui 230026,China;State Key Laboratory of Satellite Ocean Environment Dynamics,Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou,Zhejiang 310012,China;College of Physics and Electronic Information,Anhri Normal University,Wuhu,Anhrvi 241000,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,安徽合肥230031 [2]中国科学技术大学,安徽合肥230026 [3]自然资源部第二海洋研究所,卫星海洋环境动力学国家重点实验室,浙江杭州310012 [4]安徽师范大学物理与电子信息学院,安徽芜湖241000

出　　处：《中国激光》2021年第11期213-220,共8页Chinese Journal of Lasers

基　　金：国家重点研发计划(2016YFC1400604,2019YFB2006003)。

摘　　要：涡动相关法作为直接观测湍流运动的方法,是研究潜热通量和CO_(2)通量的重要手段。本团队基于可调谐半导体激光吸收光谱技术研制了激光气体分析仪,用于涡动相关法的海气通量分析。选用7181cm^(-1)处的H_(2)O吸收谱线和4990cm^(-1)处的CO_(2)吸收谱线,利用信号采集处理技术及导数谱浓度反演方法实现100Hz时间分辨率的目标气体浓度的计算,并根据计算结果评估得到H_(2)O分析仪的检测限约为8.17×10^(-6),CO_(2)分析仪的检测限约为0.40×10^(-6),时间分辨率为100 Hz。将集成的气体分析仪安装在烟台国家卫星海洋定标海上平台上进行真实的海气通量探测,并将探测结果与LICOR7500-H_(2)O/CO_(2)分析仪的测量结果进行了对比。从实验结果看,所研制的激光气体分析仪具有更高的时间分辨率,更易捕捉湍流运动的微小变化,具有广阔的应用前景。Objective As a method for directly observing turbulent motions without parametric assumptions,the eddy correlation method is undoubtedly the most advanced and preferred flux observation method at present.This method is widely used in ecological flux observations.The basic equipment of the eddy-related measurement system mainly includes a three-dimensional ultrasonic anemometer and a gas analyzer,which calculates the flux value using the covariance of the vertical wind speed and concentration fluctuation.To capture tiny concentration variables,the concentration measurement method is crucial.Moreover,the accuracy and sampling frequency of the instrument have high requirements.The commercial gas analyzers use nondispersive infrared technology,which can only achieve a time resolution of 20Hz,resulting in a loss of high-frequency data.Based on this research background,a new type of gas analyzer for eddy-related systems must be designed,which can achieve high-frequency flux measurements.Methods A laser gas analyzer is developed using laser absorption spectroscopy technology.First,the absorption lines of H2O and CO2 molecules near 7181and 4990cm-1,respectively,are simulated based on the HITRAN2012database.Second,open-path structures are designed based on the absorption intensity of two gas molecules.Third,a miniaturized electronic measurement system is designed,which facilitates laser drive,signal acquisition and processing,and data storage.Thereafter,concentration results are calculated using derivative absorption spectroscopy.To analyze the correlation between a known concentration and the peak value of derivative spectrum signal,the integrated instrument is tested and analyzed in the laboratory using CO2standard gas with different concentrations.Finally,the integrated gas analyzer is installed on the Yantai National Satellite Ocean Calibration platform for one week to detect real sea-air flux and compared with the LICOR7500-H2O/CO2analyzer.Results and Discussions We conduct performance tests on the developed prototyp

关 键 词：光谱学 气体分析仪 涡动相关法 通量探测 

分 类 号：O436.2[机械工程—光学工程]