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Vacuum Processing Technique for Development of Primary Standard Blackbodies



Magdalena Navarro, Sally Bruce, B. Carol Johnson, A V. Murthy, Robert D. Saunders


Blackbody sources with nearly unity emittance that are in equilibrium with a pure freezing metal such as gold, silver, or copper are used as primary standard sources in the International Temperature Scale of 1990 (ITS-90). Recently, a facility using radio-frequency induction heating for melting and filling the blackbody crucible with the freeze metal under vacuum conditions was developed at the National Institute of Standards and Technology (NIST). The blackbody development under a vacuum environment eliminated the possibility of contamination of the freeze metal during the process. The induction heating, compared to a resistively heated convection oven, provided faster heating of crucible and resulted in shorter turn-around time of about 7 h to manufacture a blackbody. This paper describes the new facility and its application to the development of fixed-point blackbodies.
Journal of Research (NIST JRES) -
104 No. 3


blackbody sources, fixed-point blackbodies, ITS-90, radiance temperature, rf furnace


Navarro, M. , Bruce, S. , Johnson, B. , Murthy, A. and Saunders, R. (1999), Vacuum Processing Technique for Development of Primary Standard Blackbodies, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD (Accessed April 21, 2024)
Created May 31, 1999, Updated October 12, 2021