Radiation Temperature Measurement Method And Technique Of Infrared Materials At High Temperatures

In the applications of infrared optical materials with semitransparent radiationproperties, it is necessary to carry out the experiments of optical and mechanicalproperties of infrared optical materials at thermal environment conditions. Therefore,monitoring the temperatures of infrared materials is very important in theexperiments. According to the application requirements of the multispectral zincsulfide infrared material, this paper presents the radiation temperature measurementmethod of ZnS material. The research work includes the analysis of radiativeproperties of the multispectral ZnS at high temperatures, the numerical simulation oftemperature distributions based on radiation-conduction coupled heat transfer of thesemitransparent medium, and the analysis of radiation inverse problem ofsemitransparent medium temperature measurements.First, this paper indicates the investigation of the surface spectral radiativeproperties of multispectral ZnS, and the establishment of the heat radiation transferequation for various boundary conditions. The analysis is presented to the surfaceeffective radiation properties of the multispectral ZnS at high temperatures bynumerical simulation method, which includes the variation of the medium surfaceeffective radiation intensity, the effective emissivity with the temperature andspectrum, on the conditions of isothermal, the linear and the power exponentdistributions of temperatures. In the case of measuring the infrared materialstemperature by the infrared thermal imager, this paper presents the spectraloptimization and the further investigation of the radiation properties of the mediumwithin the range of optimization spectral. After the analysis of the radiation propertiesof the multispectral ZnS, this paper shows much important basic data for theconsequent radiation heat transfer calculation and non-contact radiation temperaturemeasurements.Second, radiation-conduction coupled heat transfer problems on infraredmaterials are discussed. The Monte-Carlo method is used to calculate the temperaturedistributions of the translucent medium in knowledge of the boundary conditions. Theresults will provide the data of the inverse problems of the radiation temperaturemeasurement for reference.At last, the text describes the inverse problems of the radiation temperaturemeasurement, which belongs to the nonlinear inverse problems field. This part is the basis of theoretical methods of the realization of measuring the translucent mediumtemperature non-contact. The inversion model of the multispectral radiationtemperature measurements is established for the one-dimensional emission,absorption and non-scattering medium. The inverse problem is solved using theLevenberg-Marquardt method to construct the temperature profile. Simultaneouslythe effects of the measurement errors on the accuracy of the inverse calculations arestudied.