摘要
CO2和H2O是大气中两种重要的温室气体,对生态系统中CO2和H2O的浓度进行在线监测可用于分析环境及气候变化。选择CO2和H2O的近红外吸收谱线,利用可调谐半导体激光吸收光谱技术结合自动增益调节技术设计了开放式CO2和H2O在线检测仪。在中国科学院禹城综合试验站进行了1238m光程下,20Hz时间分辨率的连续观测实验,结果表明自动增益调节解决了开放光路检测时探测信号幅度大幅变化问题。监测点的CO2浓度具有白天低,夜间高的日变化周期性。与同场地涡度相关系统的LI-7500对比测量,数据一致性较好。该检测技术灵敏度高、响应速度快、免采样,实现了大尺度区域生态系统中CO2和H2O浓度的稳定、连续、在线检测。
CO2 and H2O are the important greenhouse gases in the atmosphere. On-line monitoring of CO2 and H2O concentrations in ecosystem can be used for analyzing environment and climate change. With the near-infrared absorption lines of CO2 and H2O, CO2 and H2O on-line detection instrument in open-path based on tunable diode laser absorption spectroscopy （TDLAS） technology and automatic gain adjustment technology is designed. The continuous observation experiment is carried out in Yucheng Integrated Experimental Station, Chinese Academy of Sciences with the time resolution of 20 Hz in 1238 m optical path by this instrument. The results show that the problem of large signal intensity fluctuation in open-path detection is solved by automatic gain adjustment. The CO2 concentration in site has an obvious diurnal periodicity that the concentration is low in the daytime and high at night. Comparing with LI-7500 of eddy covariance system, the data consistency is better. This technology has the characteristics of high sensitivity, fast response and without sampling, so the stable and continuous CO2 and H2O on-line detection is achieved in large-scale regional ecosystem.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2014年第1期227-231,共5页
Chinese Journal of Lasers
基金
中国科学院知识创新工程重要方向项目(KZCX2-YW-JS408)
中国科学院重大科研装备研制项目(YZ200709)
国家重大科学仪器设备开发专项(2012YQ220119)
中国科学院合肥物质科学研究院青年人才基金(Y03RC21122)
关键词
激光技术
大尺度区域
自动增益调节
温室气体
laser technique
large-scale region
automatic gain adjustment
greenhouse gas
