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A Research Of The Key Techniques In Portable Raman Spectrometer And Data Processing

Posted on:2020-09-20Degree:MasterType:Thesis
Country:ChinaCandidate:Y WangFull Text:PDF
GTID:2392330596975030Subject:Optical Engineering
Abstract/Summary:PDF Full Text Request
Because of the advantages of on-site quick examination,wide detection range and sharp peaks,portable Raman spectrometer has been applied and developed in chemical industry,biomedicine,geology,food safety,petroleum and other fields.The technology of portable Raman spectrometer is very important in the field of analysis.Portable Raman spectrometer has broad development prospects.In this paper,two key technologies of portable Raman spectrometer were studied,including system design and data processing.A portable Raman spectrometer system with small size and high resolution was designed.Simultaneously,excellent computer software and data processing algorithm were designed.The following work was conducted in this paper:1.The theoretical model of portable Raman spectrometer was studied.The structure and function of the important subsystems of the portable Raman spectrometer were analyzed in detail.The important subsystems include laser source system,Raman probe system,and spectroscopic system.2.In the research of the portable Raman spectrometer optical system,the important part of it:spectroscopic system was analyzed.Several common structures of the spectroscopic system were analyzed and their advantages and disadvantages were compared.A new Raman spectroscopic system based on flat field holographic concave grating structure was designed.Then the mathematical relationship between structural parameters and aberrations of the flat field holographic concave grating spectroscopic system was derived and established.A scheme for aberration optimization was proposed.The simulation shows that the resolution of the designed spectroscopic system was better than 5cm-1,and the size was only 12.6cm×7.6cm×2.0cm.This was in line with the goal of miniaturization and high resolution.3.The drive circuit design of the S11511-1006 CCD selected for the design of the portable Raman spectrometer system was studied.The FPGA-based CCD timing control system was designed,and the QuartusII and Modelsim simulations were combined to verify that the designed nine timing drive signals met the characteristics of the three working phases and the phase relationship between them.4.The data processing algorithm of portable Raman spectrometer was studied.A graphical user interface for the portable Raman spectrometer on the PC side was designed.The principles of several denoising algorithm and stray light removal algorithm were analyzed in detail.Each algorithm was used to process the experimental spectral data.Then the differences of Raman spectra processed by different algorithms were compared,and the advantages and disadvantages of each algorithm was analyzed.It laid the foundation for the processing system of liquid concentration quantitative detection algorithm based on Raman spectroscopy.5.Raman spectroscopy based liquid concentration quantitative detection algorithm processing system was proposed and applied to the alcohol concentration experiment to verify its correctness.The R~2 value of the established quantitative model of alcohol concentration was better than 0.9994.Alcohol concentration could be accurately predicted by this method.
Keywords/Search Tags:portable Raman spectrometer, flat field holographic concave grating, CCD driving, data processing
PDF Full Text Request
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