Kunming Institute of Physics, Kunming 650223, China.
Yunnan Normal University, Kunming 650029, China.
Int J Environ Res Public Health. 2022 Oct 7;19(19):12828. doi: 10.3390/ijerph191912828.
During industrial operations and in confined places, carbon monoxide (CO) may collect in harmful proportions if ventilation is insufficient or appliances are not properly maintained. When the concentration of CO is too high, it might result in suffocation, coma, or even death. The detection of tiny concentrations of CO plays an important role in safe production. Due to the selective absorption of specific wavelengths of light by gas molecules, lasers have a wide range of applications in the field of gas detection. In this paper, a tunable diode laser absorption spectroscopy (TDLAS) system for CO detection was constructed using an interband cascaded laser (ICL) with a central wavelength of 4.625 μm. The modulated signal generated by the FPGA module was output to the laser controller to modulate the laser. The signal received by the detector was input to the FPGA module. After lock-in amplification, the second harmonic signal of high frequency modulation was output. Several concentrations of CO that were dispersed via static gas distribution were identified. A CO detection system with an open optical path was constructed, and the detection distance was about 8 m. The minimum detectable concentration is around 10.32 ppmm. The concentration of CO in the open optical path was 510.6 ppmm, according to the calibration of the detected concentration. The remote detection system based on TDLAS using an ICL can be used to monitor CO in the open optical path.
在工业操作和密闭场所，如果通风不足或设备维护不当，可能会积聚有害比例的一氧化碳 (CO)。当 CO 浓度过高时，可能会导致窒息、昏迷甚至死亡。检测微量 CO 浓度对于安全生产至关重要。由于气体分子对特定波长光的选择性吸收，激光在气体检测领域有广泛的应用。本文构建了一种基于 4.625μm 中红外半导体激光的可调谐二极管激光吸收光谱（TDLAS）系统，用于 CO 检测。FPGA 模块产生的调制信号输出到激光控制器，以调制激光器。探测器接收到的信号输入到 FPGA 模块。经锁相放大后，输出高频调制的二次谐波信号。对通过静态气体分布分散的几个 CO 浓度进行了识别。构建了具有开放式光路的 CO 检测系统，检测距离约为 8m。最小可检测浓度约为 10.32ppmm。根据检测浓度的标定，开放式光路中 CO 的浓度约为 510.6ppmm。基于 ICL 的 TDLAS 远程检测系统可用于监测开放式光路中的 CO。
