response(faster than few millisecondand low detection limitation(100ppbv,and it could be easily assembled to a portable gas monitor.Furthermore,Ne—arinfrared light source and detector are chosen in the pared to traditional m—idinfrared apparatus,the total cost of these devices can be cut down.Optical fiber can be used to
获得被选定的待测气体特征吸收线的吸收光谱 ,从而对污染气体进行定性或者定量
分析。在大气痕量气体和气体泄漏的监测中 ,为了提高探测的灵敏度 ,一般会根据具
体情况对激光器采取不同的调制技术如波长调制、振幅调制、频率或者位相调制等
,
同时和长光程吸收池相结合使用 ,并辅之以各种噪声压缩技术。 TDLAS 不仅精度较
年月日
目录
摘要 (2
英文摘要 (2
第一章第三章红外吸收原理及优点 (8
第四章 CO 的吸收谱线 (11
第五章可调谐二极管激光红外吸收光谱实验原理 (14
第六章可调谐二极管激光吸收光谱实验装置 (19
第七章结论 (24
参考文献 (25
摘要
可调谐二极管激光吸收光谱 (TDLAS 技术是利用二极管激光器的波长调谐特性 ,
高 ,选择性强而且响应速度快 ,已经广泛用于大气中多种痕量气体的检测以及地面的
痕量气体和气体泄漏的检测。本文介绍了一套可调谐二极管激光吸收光谱检测大气
中一氧化碳浓度的实验装置 ,这套装置具有灵敏度高、检测限低 (ppb 量级、易于集
成为便携式痕量气体检测仪等优点 ,系统选用近红外光源和探测器 ,与传统的中红外 波长工作器件相比 ,成本得以降低。近红外波长光信号利用光纤传输 ,替代了传统的 复杂光路系统 ,使器件结构小型化。若激光器的调谐波长范围能覆盖 1.3—1.8 μｍ或 者在光路中装配几台窄范围可调偕激光器实现波长扫描范围覆盖
毕业论文 (设计
可调谐二极管激光吸收光谱法检测 CO 气体的研究 The Study of Remote Sensing CO Concentration Based on Tunable Diode Laser Absorption Spectroscopy
姓名与学号 3021121123 指导教师 年级与专业 10 级信息工程 所在学院和系信息学院光电系 毕业论文 (设计任务书 一、题目 :可调谐二极管激光吸收光谱法检测 CO 气体的研究 二、指导教师对毕业论文 (设计的进度安排及任务要求 : 起讫日期 200 年月日至 200 年月日 指导教师 (签名职称 三、系、研究所审核意见 : 负责人 (签名
transmit near—infrared optical signal instead of traditional complex system,then the structure would become miniaturization.if the laser wavelength could be tuned in covering the range of 1.3-1.8 μ m or installing few narrow DFB tunable lasers to cover the range of 1.3-1.8 μ m,simultaneous monitoring of the major atmospheric pollution gases including C02、CH4、CO、CH20、H2S、NH3 、HCI 、C2H2 and so on could be realized.
1.3— 1.8 μ m则, 可同时实现对大气中诸多重要痕量气体如 CH20、 H2S、NH3 、HCI、 C2H2 等的同步监测。
C02、CH4、CO、
关键词 :光谱学 ;可调谐二极管激光 ;怀特池 ;一氧化碳 ;大气质量监测
Abstract
Tunable diode laser absorption spectroscopic(TDLAS technology applies the wavelength tunable characteristics of diode lasers to gain the absorption spectroscopy of the selected absorption line of the target gas for the qualitative and/or quantitative analysis of the pollution gases in air.In order to get the required sensitivity in trace gas monitoring and gas leak detection, based on the idiographic requirements it generally needs to adopt different laser modulation techniques like wavelength modulation,amplitude modulation,frequency or phase modulation and so on,with combination of long path absorption cell and assistance of various noise suppression techniques.TDLAS has significant advantages not only in sensitivity and high selectivity but also in rapidity of response.It has been extensively utilized in monitoring of various pollution gases in troposphere and atmosphere,and also in location the source of toxic or hazardous gas leak.The article introduce a TDLAS—based instrument recently developed by our group for the measurement of CO in atmosphere.This instrument possesses advantages of fast