光子学报, 2017, 46 (11): 1128003, 网络出版: 2017-12-08
一种高精度中红外大气甲烷传感系统的研制
Highly-Accuract Mid-Infrared Atmospheric Methane Sensor System
红外光谱学 可调谐半导体激光器 气体检测仪 甲烷检测 Infraed spectroscopy Tunable diode laser Gas detection Methane measurement
摘要
报道了一种采用中红外室温连续带间级联激光器(ICL)的高精度大气甲烷检测系统.使用的ICL激光器的发光波数范围为2 998.4~2 999.6 cm-1, 覆盖甲烷在2 999.06 cm-1处的较强吸收峰.为增强气体吸收, 采用容积为220 mL、吸收光程为54.6 m多通池作为气体吸收池.采用LabVIEW平台和数据采集卡, 产生激光器扫描及调制信号, 同时获取探测器信号并采用数字运算提取二次谐波.实验结果显示, 当传感器系统的平均采样时间为3.3 s时, 传感器系统的阿伦方差为11.2 ppbv.采用该系统对实验室内外空气中甲烷浓度进行了长时间的测量, 证实该传感器系统具有较强的工程实用价值.
Abstract
A highly-accurate atmospheric CH4 sensor system using mid-infrared room-temperature Continuous-Wave (CW) Interband Cascade Laser (ICL) was reported. The emitting wavenumber range of the ICL is from 2 998.4 to 2 999.6 cm-1, which covers a strong CH4 absorption line at 2 999.06 cm-1. In order to enhance CH4 absorption, a multi-pass gas cell with a volume of 220 mL, optical path length of 54.6 m was employed. A LabVIEW platform as well as a Data Acquisition Card (DAQ) was used to generate the scan and modulation signal of the ICL and extract the second harmonic signal from the detector output signal. Experimental results showed that when the averaging sampling time was 3.3 s, the Allan deviation of the sensor system was 11.2 ppbv. This sensor system was used to measure the atmospheric CH4 inside and outside the laboratory for a long time, and it is proved to be of great practical value in engineering.
叶玮琳, 何迅, 孟永贤, 郑志丹, 郑传涛. 一种高精度中红外大气甲烷传感系统的研制[J]. 光子学报, 2017, 46(11): 1128003. YE Wei-lin, HE Xun, MENG Yong-xian, ZHENG Zhi-dan, ZHENG Chuan-tao. Highly-Accuract Mid-Infrared Atmospheric Methane Sensor System[J]. ACTA PHOTONICA SINICA, 2017, 46(11): 1128003.