Research Of (100?400)K Vacuum Infrared Radiance Temperature Standard Blackbody Source

In order to meet the urgent need of China's spaceflight infrared remote sensing instruments for infrared radiance temperature traceability,the National Institute of Metrologye established a set of Low Background Radiance Temperature National Standard Facility in 2015,with temperature ranges from 190 K to 340 K,which satisfies the requirements of value measurement criteria in the major space engineering and model planned in China,whether in the current or in the future.For the purpose of further improving the ability and level of measurement and calibration in the infrared remote sensing satellite,it is indeed very urgent to develop a(100 ~400)K Vacuum Infrared Radiance Temperature Standard Blackbody Source,in order to extend the temperature range of the Low Background Radiance Temperature National Standard Facility in China.The research content of this topic is as follows:Developed a device of Vacuum Radiance Temperature Standard Blackbody Source with a temperature range of(100 ~ 400)K,the design of the device mainly composes of 4 parts,includes the design of cavity,design of black body leak-proof heat,design of temperature control method,design of temperature measurement method,etc.The cavity material is copper,the cavity shape is cylinder-cone,the bottom cone angle of the cavity is 120°,the cavity inner diameter is 40 mm,the opening diameter is 30 mm,the total length of the cavity is 315 mm,and the inner wall of the cavity is sprayed with NEXTEL Velvet-Coating 811-21,the emissivity of this coating is 0.96.The effective emissivity of the cavity is better than 0.9998.The temperature control scheme uses liquid nitrogen refrigeration and 3-zone PID temperature control to achieve temperature control in the black body radiation source(100 ~ 400)K range.The axial temperature and cavity bottom temperature of the blackbody cavity are collected and measured by a precision platinum resistance thermometer and an ASL-F500 temperature measurement bridge.The test results show that the axial temperature uniformity of the black body is better than0.120 K,and the temperature stability at the bottom of the cavity is better than 0.020K/20 min.The consistency of the thermometers are tested at room temperature andthe difference in thermometers over 20 min are better than 0.021 K.According to the test results of blackbody axial temperature uniformity,the effect of the cavity axial temperature uniformity on the blackbody cavity normal emissivity is calculated by the Monte Carlo method.The results show that the temperature uniformity of the cavity normal emissivity.The effect is within 0.003%and meets the requirements of the technical specifications.The uncertainty of the black body radiation source is evaluated,and the uncertainty of the synthesized standard in the wavelength range of(8 ~ 16)?m is better than 0.030 K.