1College of Information Science & Technology, Beijing University of Chemical Technology, Beijing 100029, China
2School of Electronics and Information, Hangzhou Dianzi University, Hangzhou 310018, China
3School of Architecture, Tianjin University, Tianjin 300072, China
For natural gas distribution monitoring, it is very important to measure the CO2 isotope with high precision. In this paper, the tunable diode laser absorption spectrum (TDLAS) technology was adopted to realize the high precision CO2 isotope measurement through the absorption spectrum line of 13CO2/12CO2 at 4.3 μm. The measurement system consisted of a mid-infrared interband cascade laser (ICL) operating in a continuous wave mode, a long-path multipass cell (MPGC) and a mid-infrared mercury cadmium telluride (MCT) detector. Aiming at the problem that the intensity of 13CO2 and 12CO2 absorption spectra was affected by the temperature, an MPGC high precision temperature control system was developed. In the experiment, five CO2 gases of different concentrations were configured to calibrate the measurement system, and the response linearity was up to 0.999 6. The results show that when the integral time is 92 s, the isotope measurement precision is as low as 0.013 9‰, which has practical application value.
Yue Hou, Kejin Huang, Guanyi Yu, Pengquan Zhang. Development on high precision CO2 isotope measurement system based on infrared TDLAS technology[J]. Infrared and Laser Engineering, 2021, 50(4): 20200083