Vacuum Processing Technique for Development of Primary Standard Blackbodies

Published

June 1, 1999

Author(s)

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

Abstract

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.

Citation

Journal of Research (NIST JRES) -

Volume

104 No. 3

NIST Pub Series

Journal of Research (NIST JRES)

Pub Type

NIST Pubs

Keywords

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

Citation

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 October 8, 2025)