第21卷第11期 2013年11月
1004-924X(2013)11-2771-07
文章编号
光学精密工程
Optics and Precision Engineering
Vol. 21No. 11
Nov.2013
利用可调谐半导体激光吸收光谱法同时在
线监测多组分气体浓度张志荣*，夏滑，董凤忠，庞涛，吴边
（中国科学院安徽光学精密机械研究所安徽省光子器件与材料重点实验室，安徽合肥230031）
摘要：由于线宽窄，可调谐半导体激光吸收光谱技术（TDLAS)一般情况下只能对一种气体进行检测。为了实现多气体同时或近同时在线检测，本文以1578nm-H，S和1747nm-HCI混合气体同时在线监测为例，研究了3种检测方法：（1) 同频10kHz正弦波和两路同频30Hz不同步的分时锯齿信号法；（2)同频10kHz正弦和30Hz锯齿信号的光开关检测法；(3)多赖(10kHz和20kHz正弦信号)正弦调制法。实验结果表明：分时锯齿信号法除幅值略有微小变化外，在使用前后对测试结果影响很小；光开关法在切换过程瞬间会略有不稳定，但不影响后期的浓度反演；多频正弦法的信噪比和抗干扰能力均有所提高，进行HCI探测和H,S探测时，信噪比在激光器关闭和打开情况下分别提高了0.95倍和3.17
倍。以上3种方法操作简单，可以方便地实现多气体组分的同时在线监测，提高了TDLAS仪器的竞争力。关键调：可调谐率导体激光吸收光谱(TDLAS)；多组分气体；分时锯齿信号；光开关；多频正弦调制
中图分类号：0433.1
文献标识码：A
doi; 10. 3788/OPE. 20132111. 2771
Simultaneousandon-linedetectionofmultiplegasconcentration
withtunable diode laser absorption spectroscopy ZHANGZhi-rong'，XIAHua，DONGFeng-zhong,PANGTao，WUBian CAnhui Provincial KeyLaboratory of Photonic Devicesand Materials
Anhui Institute of Optics and Fine Mechanics,ChineseAcademy of Sciences,Hefei 23003l,China)
Correspondingauthor.E-mail;ghangzr@aiofm,ac.cn
Abstract: Generally, Tunable Diode Laser Absorption Spectroscopy (TDLAS) can detect only one kind of gas because of its narrow line-width. To detect the multi-component gas in real time simulta-neously or near simultaneously, three kinds of detection methods were reported by taking 1 578 nm H, S, 1 747 nm-HCI and N, mixture for examples. The three methods are called timeshare-sawtooth method (1o kHz sin wave, 3o Hz asynchrony sawtooth wave), optical-switch method (same frequency 10 kHz sin wave, 30 Hz sawtooth wave) and multi-frequency modulation method (10 kHz and 2o kHz sin wave). The experimental results for the three methods show as follows: the method one gives fe-wer effects on measuring results apart from amplitude changes, The method 2 shows slightly unstable
收稿日期：2013-07-19；修订日期：2013-08-20.
基金项目：国家自然科学基金资助项目（No.11204320）