Realising the redefined kelvin

Short Name: Real-K, Project Number: 18SIB02
Image of worker measuring temperature at industrial site
Temperature inspection

Bringing the kelvin redefinition into practical reality while extending the life of current scales

Temperature measurement techniques are being developed that require reference only to primary constants, such as noise thermometry at very low temperatures and radiometry at high temperatures. Redefinition of the kelvin focuses attention on practical realisation of primary thermometry, expected to lead to a transformation in measurement certainties without need for recalibration. However, primary thermometers remain complicated to use, so scales derived from measurements of other quantities are still required but with revisions, particularly at extreme temperatures.


The project tested primary thermometry approaches at temperatures greater than 1300 K and less than 25 K to kick-start the process of making these methods competitive. It also extended the life of the currently defined scale to allow time for primary methods to develop, and for thermal parameters of gases with potential for replacing mercury as a reference point to be determined. Easing the transition to primary thermometry in this way should enable in-situ traceability at lower cost, in applications such as remote monitoring in manufacturing and the nuclear power sector.


This project builds on from EMRP project SIB01 InK and EMPIR project 15SIB02 InK 2.


Project website
Coulomb Blockade Thermometry on a Wide Temperature Range

Proceedings of 2020 Conference on Precision Electromagnetic Measurements (CPEM 2020)

Other Participants
Aalto-korkeakoulusäätiö sr (Finland)
Federal State - Owned Unitary Enterprise "All Russian Research Institute for Optical and Physical Measurements" (Russian Federation)
Fondazione Bruno Kessler (Italy)
Helmut Schmidt Universitat Universitat der Bundeswehr Hamburg (Germany)
National Institute of Metrology - NIM (China)
Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences (China)
Uniwersytet Warszawski (Poland)