Research On Key Components Of Gas Raman Spectrometer Based On Cavity Enhancement

Online gas measurement analysis technology plays a very critical role in many areas such as oil exploration,petrochemicals,industrial steel production and its process monitoring.However,due to the difficulty of deep exploration,more advanced technology is needed.This written summary attempts to design a kind of Raman laser gas analyzer to detect and examine the mixed gas.The system can detect many kinds of gases using high precision in a wide range of environments and conditions all while operating with ease.The summary begins by discussing the background and innovative points of the subject,theoretical knowledge of several common Raman spectrometers that are presented,composition,characteristics,application of Raman spectroscopy that is studied emphatically and explains the reason for choosing Raman spectroscopy as topic from many aspects and levels.Also,it analyzes the research status of Raman spectra and its cavity at home as well as overseas while it introduces several kinds of methods which are commonly used in gas detection to prove the advantages and feasibility of the Raman gas detection method.This shows that the purpose of this research provides a theoretical basis for the construction of the experimental system and highlights the significance and necessity of new Raman gas system.In addition,the report expounds the basic knowledge of laser,common laser and optical cavity while it explains the reason of why it chooses the He-Ne laser and optical cavity for analytical building analyzer.The principle of gas Raman scattering is introduced from quantum theory,providing the theory basis to establish gas Raman spectrum analyzer.Furthermore,based on a series of theoretical studies,the gas Raman spectroscopy analyzer is constructed.The instrument uses a 25 m W He-Ne laser source to generate excitation light,which has a wavelength of 0.6328?m,and uses high reflectance lens to build a resonant cavity.This report also use cavity enhancement principle to generate the Raman signal and uses an aperture diaphragm to effectively suppress stray light in the gas chamber and increase the signal-to-noise ratio all while the multi-window and multi-component gas Raman online detection is implemented.Through the small signal amplification design of the signal acquisition circuit of the back of the photoelectric detector the detection sensitivity and signal-to-noise ratio of the p A level is determined and the complexity of the system is reduced.In conclusion,the subject selected the common six kinds of gases in the oil as a sample to be tested in a standard atmospheric pressure with a flow rate of 100 m L/min while measuring quantity and analyzing quality,and three type gases need to be tested respectively: 100 % of gas tested,0.1 % of gas tested and 100 % pure argon gas.The research shows that the analyzer can effectively detect the gas component and concentration of the mixed gas and the detection range of the tested gas can range from 0.1% to 100%.