基于TDLAS和ICL的紧凑中红外痕量气体探测系统

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。

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

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 (CH₄) measurements and the single-floor structure sensor was used for formaldehyde (CH₂O) 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 CH₄ and CH₂O concentration measurements, respectively. In addition, the two-structure system was used for CH₄ and C₂H₆ 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.