Research On Key Technologies Of Gas Remote Sensing Based On Open Path Tunable Diode Laser Absorption Spectroscopy

Optical remote sensing is an effective way to detect the dangerous gas leakage and monitor polluted gas.Remote sensing system can not only detect gas concentrations in places where hazards and monitoring are difficult,but also enables real-time online monitoring of a wide range of gases.According to the requirement of development and reality,this paper designs and realizes the adaptive targeting control and the real-time online monitoring of methane gas of reflective remote sensing system.The technical principle of the remote sensing system is based on the tunable diode laser absorption spectrometry(TDLAS)technology.The design of the adaptive targeting control can achieve the adaptive targeting of the transceiver unit and the reflection unit.The stability and environmental adaptability of remote sensing system are improved effectively,and maintenance cost is reduced.The real-time on-line monitoring design can realize the real-time display and recording of methane gas concentration,and generate leakage signals in time.This paper focuses on an adaptive targeting telemetry system based on open light TDLAS technology,designs and implement adaptive targeting control and on-line monitoring of methane.The main contents of this paper include:1.The basic theory of infrared spectrum absorption is described,and the line absorption strength and linear function are introduced.The principle of TDLAS detection technology is introduced,and the theoretical basis of gas detection by open light path is given.2.The design of telemetry system is introduced in detail,including optical system design and electrical system design.The optical system design is mainly the optical structure design of the transceiver unit and the reflection unit.The principle of type selection and performance parameters of the main components of the system are introduced,and the design and principle of the driving module,temperature control design,conversion circuit and data acquisition system are introduced in detail.3.Design of remote sensing system program based on LABVIEW software to realize adaptive targeting and real-time online monitoring of gas.Programming includes signal generation design,signal acquisition and data processing design,adaptive sighting control design,feature spectrum extraction and methane concentration inversion design.4.Experimental analysis of remote sensing system.The high frequency noise and random noise of signal are removed by filtering and averaging,and the signal quality is improved.The adaptive targeting experiment and the on-line monitoring experiment of methane were carried out through the system.The performance of the system is verified by experiments.