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With China's energy situation and Air Pollution in the increasingly grim, the emission of gaseous pollutants detection technology development by the attention. Tunable diode laser absorption spectroscopy (Tunable diode laser absorption spectroscopy, the TDLAS) because of its high accuracy, in response to the rapid, etc., become the fastest growing gas detection methods. Previous studies on TDLAS primarily focused on gas in the laboratory absorption pond gas concentration, temperature, flow rate and other parameters, but with the development of technology, the research direction gradually open path gas monitoring aspects of development. This thesis is designed and developed telemetry the telescope transceiver system, this equipment detectors and lasers integrated set of equipment, not only to save space and cost, but also easy to carry and use. Online monitoring for better gas. This paper describes the TDLAS measurement principle, the principle depth analysis involves molecular absorption spectroscopy. Test bed structures, as well as related to the experimental device and its principle is described. Firstly, in the laboratory case, using conventional measurement methods, respectively, with the direct measurement and wavelength modulation method, nine different concentrations of CH4 gas detection, and experimental data analysis, which compared the direct measurement method and wavelength The characteristics, advantages and disadvantages of the modulation method. On the basis of the above experimental the telemetry the telescope transceiver system, a two-step, gradually realize online monitoring of CH4. The first part is the part of the calibration of the optical path. For the performance of the of test telemetry telescope transceiver system, and detecting the stability and accuracy of the experimental system. The second part of the online monitoring component. Record 300S by spraying a certain amount of methane gas in the air, and the trend of the peak value of the second harmonic signal with the methane flow rate change. Applications tunable laser absorption spectroscopy techniques based on to design telemetry telescope transceiver system, build a test-bed to complete a long-distance open-path methane gas telemetry experiments to verify the stability and accuracy of the system, detection results compared with standard results, found both consistent and high linear fit coefficients greater than 0.99. On this basis, the online monitoring changes in methane concentration in 300 seconds, and the next experimental project. Presented in this paper based on the tunable laser absorption spectroscopy telemetry methods, the results are accurate, and has high practical value and promotion prospects.
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