Dissemination of thermodynamic temperature using Fe-C and Pd-C high-temperature fixed point cells

Abstract

This paper presents the utilization of Fe-C and Pd-C high-temperature fixed points (HTFPs) for the dissemination of thermodynamic temperature and the International Temperature Scale of 1990 (ITS-90). Initially, the HTFPs were manufactured and evaluated to determine the thermodynamic temperature during the melt of these materials. Subsequently, the cells were employed to compare the local realization of the International Temperature Scale of 1990 (ITS-90) in an ISO 17025 accredited industrial laboratory and two National Metrology Institutes (NMIs) with limited experience in operating HTFPs. The HTFPs were installed in Alumina tube furnaces, which have a maximum operating temperature of approximately 1600 °C. The investigation focused on the Fe-C (1153 °C) and Pd-C (1492 °C) fixed-point materials due to their suitability for realizing the temperature scale through interpolation schemes in this type of furnace. The findings of this comparative study contribute to enhancing the understanding and application of HTFPs for thermodynamic temperature dissemination.