Testing the equivalence of T and T90 primary thermometry in the range between 4 K and 303 K

Le résumé fourni par la source

We report and discuss the results obtained by an international comparison of primary thermometry capabilities which includes determinations of thermodynamic temperature T and realizations of the International Temperature Scale of 1990 (ITS-90) over the range between 4 K and 303 K. The comparison, which uses capsule thermometers of different kinds (Pt, PtCo, RhFe) as transfer standards, is notable in several aspects. Firstly, because the circulation scheme used to determine the majority of the differences (T−T90) reported here is unprecedented, with different National Metrology Institutes being alternatively responsible for the thermodynamic- or the ITS-90 calibration of the same standards. Secondly, because the comparison structure was designed to be highly redundant, based on the results of three different primary gas thermometry methods from seven laboratories and the ITS-90 calibration of 26 capsule thermometers from eight laboratories, thus providing a large number of (T−T90) determinations and facilitating the identification of issues with the local realization of either scale. Finally, because the ensemble of the results presented here, in the perspective of a dissemination of the kelvin based on its thermodynamic realization, verifies its level of consistency with the current dissemination of T90.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.