20.500.12556/RUL-167928 Realizing the redefined Kelvin extending the life of ITS-90 Following the redefinition of the kelvin, the user is presented with a more nuanced traceability route for temperature through the mise en pratique for the definition of the kelvin (MeP-K-19). Here we describe research to address several present and potential shortcomings with the current main dissemination route, namely the International Temperature Scale of 1990 (ITS-90). The ITS-90 has served the global temperature measurement community well, providing reliable, low uncertainty traceability for over 30 years. However, there are some potentially life-limiting issues for it. Among these are the impact of the main types (1 and 3) of non-uniqueness which represent an important contribution to the uncertainties achievable with the ITS-90, and the possible need to identify an alternative to the mercury triple point, a key fixed point of the ITS-90 whose use could be banned by an international treaty. Significant progress has been made in addressing these problems through a) new determinations of Type 3 non-uniqueness which have been undertaken in the range –189 °C to 156 °C; b) a comprehensive evaluation of Type 1 non-uniqueness on a large number of Standard Platinum Resistance Thermometers (SPRTs) across multiple temperature regions; c) comparison of high temperature SPRTs in pressure-controlled heat pipes to characterize Type 3 non-uniqueness between 660.323 °C and 961.78 °C and d) new designs of ▫$CO_2$▫ and ▫$SF_6$▫ cells for use with long-stem SPRTs. The fixed-point cells have been improved compared to previous versions by using purer gases and more stable and uniform temperature-controlled baths, and by the development of a flexible set-up that can accommodate both capsule and long-stem SPRTs. The effect of replacing mercury on the ITS-90 interpolating equations and uncertainty propagation has also been investigated. kelvin International Temperature Scale of 1990 standard platinum resistance thermometer scale non-uniqueness new temperature fixed-points kelvin Mednarodna temperaturna lestvica iz 1990 standardni platinasti uporovni termometer neenakost lestvice nove temperaturne fiksne točke true false true Angleški jezik Slovenski jezik Članek v reviji 2025-03-20 14:07:39 2025-03-20 14:07:44 2025-03-21 03:57:50 0000-00-00 00:00:00 2024 0 0 020002-1-020002-9 iss. 1, art. 020002 Vol. 3230 Oct 2024 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 621.317:006.91 1551-7616 10.1063/5.0234458 229648131 020002_1_5.0234458.pdf 020002_1_5.0234458.pdf 1 02ED8737B1C0A1D6001F5B8D088C8600 1df5b1f81d59d4a55e50dcf997368c4a73ba3833483a27116bab2dc77ba6c383 9770dfc2-058b-11f0-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=200856 https://pubs.aip.org/aip/acp/article/3230/1/020002/3317414/Realizing-the-redefined-Kelvin-Extending-the-life 1 4d4734bd-058b-11f0-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=200855 Fakulteta za elektrotehniko 0 0 0