Research On Measurement Method Of Blackbody Radiation Characteristics Based On FTIR

As a standard in the field of infrared radiation temperature measurement,the black body radiation source is an important guarantee for the accuracy and uniformity of radiation temperature measurement.The theory of black body radiation is the theoretical basis of radiation temperature measurement,radiation temperature measurement is widely used and rapidly developed temperature measurement technology,it is widely used in production and life,military scientific research and other fields.In the existing temperature measurement instrument verification system table and thermometer verification regulations,only the temperature standard in the blackbody radiation source equipment should be used as a measurement standard appliance for periodic verification.However,the current blackbody temperature test is based on a set of radiation thermometers with different wavelengths（or bands）as comparison radiation thermometers.By comparing the effective brightness temperature of the standard blackbody radiation source and the calibrated blackbody radiation source,the calibration is achieved.The effective brightness temperature calibration of blackbody radiation sources at the commonly used wavelengths for radiation temperature measurement cannot include all the wavelengths in radiation temperature measurement,especially the special requirements in the long wave band in the military field.In this regard,this paper selects the FTIR spectrometer as the measuring instrument to study the measurement method of blackbody radiation characteristics.The specific research content and main research results are as follows:Firstly,a black-body radiation characteristic measurement system based on FTIR consisting of a black-body radiation source group,an infrared external optical path,and an FTIR spectrometer was built.Secondly,based on the single light source method of light flux multiplier principle,the FTIR-based blackbody radiation characteristic measurement system for infrared detector by MCT detector and DTGS detector by MCT detector and DTGS detector is noted to make nonlinear measurement,and the FTIR spectral measurement system composed of DGTS detector is selected for experimental study.Thirdly,the calibration of the FTIR-based blackbody radiation characteristic measurement system was performed.The wavelengths of the FTIR spectrometer were calibrated using infrared standard substances,the radiation source size effect of the FTIR-based blackbody radiation characteristic measurement system was measured using the direct method,and the optical system was optimized.The non-linear calibration method is used to process the radiation calibration of the FTIR-based blackbody radiation characteristic measurement system.Compared with the traditional piecewise linear calibration method,the accuracy of the calibration results in this paper is verified,and the accuracy of blackbody radiation measurement is improved.Finally,for the verification of the measurement accuracy of the FTIR-based blackbody radiation characteristic measurement system,the internaltemperature field of the blackbody cavity was measured using a radiation temperature measurement method and the blackbody emissivity was calculated based on the Monte Carlo ray tracing method.And anti-performance black body true temperature based on effective brightness temperature model.The FTIR-based blackbody radiation characteristic measurement system and transfer-level standard radiation thermometers（measurement wavelengths of 3.9μm and 8 to 14μm,respectively）were used to measure blackbody radiation sources with a nominal temperature of 300 to 900℃.The experimental results show that the relative error between the measurement result of the FTIR-based blackbody radiation characteristic measurement system and the standard radiation thermometer is0.26%,which verifies the accuracy of the FTIR-based blackbody radiation characteristic measurement method,and its measurement uncertainty is better than 2.01 × 10^-3.