2022 Update for the Differences Between Thermodynamic Temperature and ITS-90 Below 335 K
Christof Gaiser, B. Fellmuth, R. M. Gavioso, M. Kalemci, В. Г. Кытин, Tohru Nakano, A. I. Pokhodun, P. M. C. Rourke, R. L. Rusby, F. Sparasci, P. P. M. Steur, Weston L. Tew, Robin Underwood, D. R. White, Inseok Yang, Jintao Zhang
Abstract
In 2011, a working group of the Consultative Committee for Thermometry published their best estimates of the differences between the thermodynamic temperature T and its approximation (T90), the temperature according to the International Temperature Scale of 1990, ITS-90. These consensus estimates, in combination with measurements made in accordance with ITS-90, are an important alternative to primary thermometry for those requiring accurate measurements of thermodynamic temperature. Since 2011, there has been a change in the definition of the kelvin and significant improvements in primary thermometry. This paper updates the (T − T90) estimates by combining and analyzing the data used for the 2011 estimates and data from more recent primary thermometry. The results of the analysis are presented as a 12th-order polynomial representing the updated consensus values for the differences and a sixth-order polynomial for their uncertainty estimates.