| This thesis is aimed at the research on the remote gas monitoring technology and application based on Fourier Transform Spectroscopy（FTIR）. Based on the theory of remote gas monitoring technology（RGMT）, a remote gas monitoring system based on FTIR is designed and constructed, which is used to measure different type of gas at different concentration. We also apply the RGMT into Tunable Diode Laser Absorption Spectroscopy（TDLAS） system, and use it to measure the concentretion of CO gas. The major work of the thesis is as follows:1) We built the mathematical model of RGMT and analyzed the factors which affected gas concentration during the sampling process. Through making the theoretical analysis and simulation, we laid the foundation of system construction and future experiments.2) A remote gas monitoring system based on FTIR is designed and constructed. We introduced the design and algorithm of the system, which was used to detect the gasoline vapors. The results show that the gas volume flow causes little influence on the measured concentration and equilibration time, with error of less than 7 %. However, the distance causes a large influence and the error even grows to 18 % with distance of 15 m. But it can be limitted to 4 % after fixing. The relationship between the vacuum pressure and the concentration is linear. Through the analysis of simulation and experiments, the measured concentration can be calibrated to match the true value, providing a reference for detection in field.3) We measured the mid-infrared spectrum of the diesel vapors, CO, and CO2. By analying the composition of the ingredients and the molecular structure, we got the way to distinguish the gasoline and diesel vapors, as well as CO and CO2 mixture gas.4) We applyed the RGMT into TDLAS system to measure the gas concentretion. According to the principle, we used the software to simulate the entire experiment. Taking CO gas as an example, we measured the second harmonic amplitude at different concentration and different temperature. |
