光学学报, 2018, 38 (5): 0512004, 网络出版: 2018-07-10
基于频分复用波长调制光谱的NO2及NH3浓度测量 下载: 695次
Concentration Measurements of NO2 and NH3 Based on Wavelength-Modulation Frequency-Division-Multiplexing Spectroscopic Technique
测量 环境光学 中红外吸收光谱 频分复用波长调制 量子级联激光器 measurement environmental optics mid-infrared absorption spectroscopy wavelength-modulation frequency-division multiplex quantum cascade laser
摘要
基于中红外量子级联激光器(QCL)以及频分复用波长调制光谱技术,实现了NO2及NH3的高精度同时测量。对中心频率在1600.0 cm
-1及1103.4 cm
-1附近的两支QCL施加不同频率的正弦调制,利用数字锁相技术得到了测量信号在不同解调频率上的二次谐波信号。搭建了一套基于该技术的开放式空气中NO2及NH3的测量系统,多次反射池的光程为60 m。利用25 cm长的参考池进行浓度标定,发现系统在较大的浓度范围内具有优良的线性响应。两种气体的检测限均小于10
-9量级。使用系统进行了24 h的气体监测,测量结果与参考仪器的结果吻合较好。
Abstract
Based on the mid-infrared quantum cascade laser (QCL) and wavelength-modulation frequency-division multiplexing spectroscopic technique, the simultaneous and high-sensitive NO2 and NH3 concentration measurements are realized. The QCLs with central frequencies around 1600.0 cm
-1 and 1103.4 cm
-1 are modulated at different frequencies. With the digital lock-in technique, the second harmonic signals are obtained by demodulating the original signals at different frequencies. A measurement system with a 60 m open-path multi-pass cell is developed for simultaneous monitoring of NO2 and NH3 in the air. A 25-cm-long reference gas cell is used to calibrate the system and it is found that the excellent linear response of the system occurs within a wide range of concentration. The detection limits for two kinds of gases are smaller than 10
-9. The real-time gas monitoring during 24 h is performed with this system and the measurement results show a good agreement with those given by the reference instruments.
陈祥, 阚瑞峰, 杨晨光, 胡迈, 姚路, 范雪丽, 何亚柏, 裴晓凡, 刘建国. 基于频分复用波长调制光谱的NO2及NH3浓度测量[J]. 光学学报, 2018, 38(5): 0512004. Xiang Chen, Ruifeng Kan, Chenguang Yang, Mai Hu, Lu Yao, Xueli Fan, Yabai He, Xiaofan Pei, Jianguo Liu. Concentration Measurements of NO2 and NH3 Based on Wavelength-Modulation Frequency-Division-Multiplexing Spectroscopic Technique[J]. Acta Optica Sinica, 2018, 38(5): 0512004.