Studying Of In-situ Gas Monitoring System Based On TDLAS

Protecting the environment and making the strategy of continuable development,is the topic of China and all the countries in the world.In the past thirty years of reformation and opening of China,we made great progress in improving the economy and people's standard of living ,at the sacrifice of a great deal of resources being consumed at a low efficiency,the natrual environment being polluted day after day and so does the entironment being deteriorated.As the carrying out of the strategy of continuable development and the improvement of people's comprehension of enviromenalism,more and more attention are concentrated on the let of contamination which is produced in the industry.People realise that the contamination produced in the industy such as petroleum,chemical, metallurgy and rubbish burning should be in-situ detected,so as to optimize the process of these industries.Then the efficiency of resources will be improved,and the amount of contamination let will be reduced.Harmful gas is the important part of contamination.In traditional way,harmful gas is detected by the non-dispersed infrared gas analyser after the dust and vapor in the gas has been taken out.The result get in this way is not credible all the time.The traditional method got the shot period of calibration ,long response time.In-situ detecting is actually out of traditional method's reach.The gas monitoring system based on TDLAS could solve all the problems that traditional method has.As the basic research of TDLAS applied in low-concentration range (ppm to ppb) gas measurements, this paper described the theory of infrared absorption spetruscopy,distinguished the universality and particularity of TDLAS,provided the gas concentrations retrieving theory and approach. Many measures are utilized to overcome the disadvantage of poor signal intensity. This investigation discussed some issues in details, such as the selection of laser source and detector, the system configuration,the application of WMS and detection of harmonious tone of WMS and the management of measurement .