Based On The TDLAS Technology Of Gas Sensor Research

TDLAS(Tunable Diode Laser Absorption Spectroscopy)semiconductor Laser Absorption spectrum technology is the use of different gas corresponding to different Absorption spectra,when the corresponding wavelength of Laser through the gas will be absorbed by the gas under test,optical power decline.The higher the gas concentration,absorption effect is more obvious,therefore,by measuring the incoming gas before and after the incident light and the ratio of the output optical power,you can determine the concentration of the gas being measured.The principle of TDLAS gas sensing system due to its own characteristics,measurement accuracy,fast response,high sensitivity,large range of test and inspection form diversification,the front-end sensing probe intrinsically safe,can be applied to most of the working conditions.And these characteristics are in industrial production,especially in the chemical industry.Precise gas measurement,not only can provide more accurate data for production to improve production efficiency and quality,but also play an indispensable role in production safety,the protection of the workers' life safety.Due to the presence of moisture condition is very low,so easy to mix with all kinds of gas,so the measurement of moisture in all gas is the most difficult.In this article mainly through the study of moisture measurement to develop TDLAS gas sensor research.Because of TDLAS technology for gas measurement principle is the same,measure the different gas only depends on the use of laser wavelength,so when after the success of the moisture measurement,only need of replacement laser accordingly and make minor adjustments to the circuit to make it into a measure other gas sensor.First,from the perspective of the TDLAS principle,this article introduces the basic principle and the technical difficulties and the research of overall sensor system.Then in detail the whole process of moisture sensor research and development,from the laser type selection,air chamber design,circuit design and software algorithm processing and final calibration test results,etc.,and expounds the technical index of the product and the comparison with the domestic and foreign advanced technology.Finally,with sensors in coal gas project,through the application of examples to show this project further research.