【作者】 涂郭结； 董凤忠； 王煜； 庞涛； 夏滑； 张志荣； 吴边；

【Author】 Guo-jie Tu,Feng-zhong DONG,Yu Wang,Tao Pang,Hua,Xia,Zhi-rong ZHANG,Bian Wu Anhui Provincial Key Laboratory of Photonic Devices and Materials,Anhui Institute of Optics& Fine Mechanics,Chinese Academy of Sciences,Hefei 230031,P.R.China

【机构】 安徽省光子器件与材料重点实验室,中国科学院安徽光机所；

【摘要】 使用可调谐激光吸收光谱技术进行气体浓度检测或其他应用时,可在吸收信号较强时采用直接吸收方案,该方案具有结构简单,易于使用,成本较低等优点。但由于直接吸收方案中有用的吸收信号叠加在很大的基底信号之上,限制了其测量精确度和分辨率。本文采用锯齿波调制电路消除叠加在吸收信号上的交流基底,结合隔直手段得到较纯净的吸收信号并放大,提高了直接吸收测量精度与分辨率。由于采用的是系统已有的调制信号,全系统将非常简单易行。更多还原

【Abstract】 For the applications of tunable diode laser absorption spectroscopy technique on gas concentration monitoring or other kinds of detection,the direct absorption scheme is often adopted when the absorption is strong enough.Direct absorption scheme possesses the advantages of simple structure,easy management,low cost and so on.However,its measurement accuracy and sensitivity is heavily limited due to the fact of the usable absorption signal superposed on the large underlay DC background.In this paper a saw-tooth modulated circuit is employed to eliminate the large background signal,combining with filtering method the clear absorption signal could be obtained and amplified,thus the measurement accuracy and sensitivity could be greatly enhanced.As the used saw-tooth circuit is part of the developed TDLAS system,therefore the method would be very simple and applicable.更多还原