基于TDLAS和ICL的紧凑中红外痕量气体探测系统

Compact mid-infrared trace gas detection system based on TDLAS and ICL

为了实现基于可调谐激光吸收光谱技术的高检测灵敏度、低功耗、小型中红外痕量气体传感器设计,结合锑化镓(GaSb)ICL和紧凑型多反射气体吸收气室(MPC)研制了基于不同结构传感光学核的两个小型TDLAS传感系统。两个传感光学核的总功率消耗为3.7 W,并通过探测甲烷(CH4)和甲醛(CH2O)分别验证了双层结构和单层结构系统的性能。实验结果表明:CH4和CH2O系统的检测灵敏度分别为5.0nL/L和3.0nL/L,测量精度分别为1.4nL/L和1.0nL/L。此外,相同配置情况下将两种结构系统应用于甲、乙烷(C2H6)同步检测,通过对校园环境中甲、乙烷进行连续66h的监测试验,验证了设计的紧凑型中红外痕量气体检测系统能够稳定有效地工作,基本满足目前民用气体测量的稳定可靠、精度高、抗干扰能力强等要求。

Two compact Tunable Diode Laser Absorption Spectroscopy(TDLAS)sensor systems were developed based on different structural optical cores.The two optical cores combine two recent developments;gallium antimonide(GaSb)-based ICL and a compact multipass gas cell(MPC),with the aim of developing a compact TDLAS-based sensor for mid-IR gas detection with high detection sensitivity and low power consumption.The two-floor structure sensor was used for methane(CH 4)measurements and the single-floor structure sensor was used for formaldehyde(CH 2O)concentration measurements,with the two optical sensor cores consuming 3.7 W of power.Detection limits of^5 nL/L and^3 nL/L with measurement precisions of^1.4 nL/L and^1 nL/L were achieved for CH 4 and CH 2O concentration measurements,respectively.In addition,the two-structure system was used for CH 4 and C 2H 6 detection under the same conditions over a period of 66 h campus.The results show that the sensors worked steadily and effectively.They can satisfy the system requirements of non-contact,online,real-time,high-precision,and rapid signal acquisition,as well as strong anti-jamming and high stability.