Automatic Calibration System For Portable Broadband Multi-channel Spectrometer

Spectrometer is known for its great and unique advantages as high accuracy,rapid measurements,extensive application and simple operation.That is why it plays an important and irreplaceable role in the analysis and testing field.In order to fully realize the function of spectrometer and ensure its precision,the process of wavelength calibration must be done not only before dispatched from the factory,but also during use.The conventional wavelength calibration method is generally to find a function about wavelength and the corresponding pixel positions,and this function is an n order polynomial.This method identifies groups of wavelength-pixel set based on experimental data,then researches to determine the function through the corresponding algorithm.Traditional methods require human involvement in the conduct,and the accuracy is not high enough.The research of this paper is to achieve automatic calibration system for portable broadband multi-channel spectrometer,then write automatic calibration software.In this paper,the design of automatic calibration system includes four parts,that is divisition of the spectral line,peak-seeking,finding the right set of pixel-wavelength,and calibration.Firstly,this paper adopts the segmentation algorithm based on image positioning,dividing the original wave automatically collected by spectrometer.Secondly,the system automatically seeks the peak of every line using bezier curve fitting method.Then by the maximum linear matching algorithms available,it can find the right sets of wavelength-pixel.Finally,these data are fitted to obtain the calibration equation.This paper designs automatic calibration software interface,which makes the operation easily and the calibration process visualized.To verify the results of the calibration,this paper designs some comparative test.The theoretical analysis and experimental results show that this method can effectively complete the calibration,and the calibration accuracy rate becomes 97.44%.It verified that the automatic calibration system for portable broadband multi-channel spectrometer is effective and reasonable and has great prospects.