| Abstract | Recent advances in high-temperature thermometry have opened up the possibility of realizing and disseminating thermodynamic temperatures above the silver point by means of both primary radiometry and radiation thermometry with the aid of high-temperature fixed points with known thermodynamic temperatures. A variety of realization schemes, denoted n = 0, 1, 2, 3, 3+, where n refers to the number of fixed points used in the realization, are described in new sections of the "Mise en pratique for the definition of the kelvin." A major advantage of this approach is flexibility, accommodating the varying resources and needs of a wide range of laboratories and/or users. This article outlines the uncertainty analysis for each of the n ≥ 0 schemes, which provides a means for assessing the suitability of any particular scheme and for selection of the appropriate fixed points. In all cases, the analysis is based on a modified Sakuma-Hattori model of the radiometer response. This model allows simple analytical expressions to be derived for all sensitivity coefficients, identification of the dominant uncertainty components, and each scheme to be easily compared. Current best estimates for each uncertainty component are given, and these are propagated to give a total uncertainty for each scheme. © 2011 Springer Science+Business Media, LLC. |
