Study On Design And Experiment Of A Special Miniature Near-infrared Spectrometer System

NIR(Near Infrared)spectroscopy is a non-contact,no need for complicated sample pretreatment process,convenient and effective analysis technology in quality and qualitative analysis of solid,liquid and gaseous objectives.And it is widely used in process and online analysis.This thesis describes the design and experimental of a micro NIR grating spectrometer with high stability to meet the demand of fluid identification in petroleum reservoir,which solved the key technical problem in developing spectrometer.It has a great meaning in scientific research and engineering application.We conduct the research of the dedicated micro near infrared grating spectrometer.In the first place,we analysis performance of the spectrometer to accord with the application in high environment temperature to meet the requirement of crude oil qualitative and quantitative analysis.In the second place,we research on the theory and design method of micro near infrared grating spectrometer whose light splitting element adopting a flat field holographic concave grating.In third place,we design and optimize the spectral image system,conduct mechanical structure and assemble technology,calibrate the spectrum and test performance of the spectrometer.Finally,we develop the dedicated NIR micro spectrometer with high stability which can be used in high environment temperature.Through testing,the wavelength range can overlie 1590.0~1873.5nm,the resolution is better than 5nm.It is proved that it can be used in the qualitative and quantitative analysis of crude oil at the temperature of 20~70?.The research work in this thesis mainly includes the following.(1)Carry on investigation of the current situation of domestic and foreign research in micro NIR spectrometer,and find the key technical obstacles.Combine reservoir environment characteristics and demand of qualitative and quantitative analysis crude,we establish the research content and the specific goal of the micro NIR grating spectrometer.(2)Research in design theory and calculation method of flat field holographic concave grating.Study on dispersion and aberration theory of the grating spectrometer and correction method of it.Trace ray in ZEMAX software,optimize the optical system and determine the structure parameters.Analysis the stray light of the system and set structures to desperate it.(3)Consider the system integration technology on space layout,material selection and integrated technology.Design mechanical structure of the instrument and assemble technology.(4)Calibrate the spectrometer.Make verification regulation to test the performance indicating reference standard.Build the test platform,carry on the test of wavelength,resolution,accuracy of wavelength,signal-to-noise ratio,temperature performance,etc.The result shows that spectral wavelength ranges from 1590 to 1873.5nm,resolution is better than 5nm,accuracy of wavelength is ±1.1nm,repeatability of wavelength is 100%.Temperature characteristics: At the temperature of 20~50?,spectra responses and intensity maintain a great consistency;Signal-to-noise ratio is larger than 1000:1.