Research Of 190K To 340K Vacuum Standard Blackbody Radiance Temperature Source

To calibrate the radiance temperature of Chinese Fengyun Meteorological satellite infrared remote sensing, NIM China proposed domestic remote sensing satellite infrared brightness temperature standard research programs, and established the Vacuum Radiance Temperature National Standard Facility(VRTSF). Wherein the 190 K to 340 K Vacuum Standard Blackbody Radiance Temperature Source is used as a traceable standard device, which is the core of VRTSF device. This essay systematically introduces the development process of the standard blackbody for VRTSF device, including the needs analysis, system design, working principles and performance evaluation, etc. The standard processes of the blackbody in the VRTSF are described in details and its key performance indicators are measured. The research results are as follows:(1) The actual needs of China's space infrared remote sensing load are summed up. Through extensive literature research and simulation calculations, the specifications and design scheme of vacuum standard blackbody radiance temperature source technical are presented.(2) The design scheme of 190 to 340 K high emissivity standard vacuum blackbody source are presented. Through preliminary experiments, it is confirmed that the alcohol bath temperature control programs and standard platinum resistance temperature measurement methods are applicable. The installation and commissioning of the complete system are conducted.(3) The blackbody performance experiments are conducted, and the blackbody cavity axial uniformity, stability and consistency of the thermometer are measured. The experiments results show that at-83 ?, the axial temperature difference of blackbody cavity is up to 0.378 ?; at 20 ?, the axial temperature difference of the blackbody cavity is 0.004 ?. In the temperature range of-83 ~ 67 ?(190 ~ 340 K), the temperature stability of the blackbody cavity is better than 0.026 ? within 30 min; at room temperature, the thermometer consistency is tested, the result is better than 0.007 ? within 120 min.(4) The vacuum standard blackbody radiation performance is evaluated. Using the axial temperature uniformity of the blackbody cavity results, the actual emissivity of the blackbody cavity is calculated which is greater than 0.9999. The uncertainties and their sources are analyzed, including cavity emissivity, thermometer calibration, thermometer stability, temperature stability of the cavity, the cavity bottom temperature uniformity and temperature meter. Experimental results indicated that,, the combined standard uncertainty for 4 ~ 14 ?m wavelength is 0.030 K. At 300 K, the combined standard uncertainty of 10 ?m wavelength is 0.016 K. Uncertainty evaluation results show that the vacuum blackbody source performance is with good quality.