Algorithm For Measuring Plasma Field Temperature Based On Multispectral Method

Since 1970s,with the rapid development of the global economy,in the field of aerospace,defense,materials,energy and other fields,the requirements for high temperature plasma field measurements are getting higher and higher.This kind of temperature field is usually characterized by high temperature,transient process,unstable environment(such as poor test environment,strong electromagnetic,vibration and other factors),and high temperature measurement precision.Commonly used at home and abroad including contact and non-contact measurement method can't meet the above requirements of temperature measurement.Multi spectral temperature measurement method is widely used in domestic and international experts because it is a non-contact temperature measurement and can be used for accurate diagnosis of uniform or non-uniform high temperature plasma field.This paper will be based on multi spectral thermometry,and aims to propose a precise measurement of high temperature plasma radiation temperature and the excitation temperature of the algorithm,to solve the defense industry and other related fields of high temperature plasma field of large range,high precision and fast response measurement needs.In multi spectral radiation measurement,the spectral emissivity is a parameter,and the spectral emissivity of the actual target is complex and related to many factors.Therefore,how to obtain the spectral emissivity of the target with high precision is the key and difficult point in the research of multi spectral radiation measurement.Experts at home and abroad have put forward the method of measuring heat,reflecting and energy to solve the problem of spectral emissivity measurement,but these methods have their own limitations and the effect is not good.Based on this problem,this paper presents a theoretical method,which is based on the basis function of the spectral emissivity of the material under different temperatures.By this method,the emission rate model according to object under different temperature condition,the dynamic change coefficients adaptively change,get the emission rate of the actual situation,so as to improve the measurement accuracy of the radiation temperature.In this paper,a very accurate mathematical model of radiation temperature measurement is established,which can further reduce the influence of spectral emissivity on temperature measurement accuracy,and ultimately improve the measurement accuracy of radiation temperature.The simulation results show that the proposed method can achieve the accuracy of 0.66%.In order to verify the improvement of the multi spectral temperature measurement algorithm,we have developed a prototype system of transient temperature measurement.The working wavelength of the system is 400?700nm,the center wavelength of spectral line extraction accuracy is 1nm,extraction of the characteristic spectral line bandwidth is less than 6nm,the response speed is less than lus,the military,defense industry and other fields in the common elements(copper,aluminum,magnesium,titanium,nickel,tungsten,iron)to achieve high precision measurement radiation temperature.The transient temperature measurement prototype system,using the temperature measurement algorithm proposed in the paper,the bromine tungsten lamp of the temperature field of the temperature experiment,but also on the laser induced metal target surface temperature plasma field temperature measurement experiment.The accuracy and reliability of the algorithm in the practical application are verified by two experiments.