Academy of Finland  
Funding decision
Applicant / Contact person Fordell, Thomas
Organisation VTT Technical Research Centre of Finland Ltd
Project title Optical Primary Thermometry
Decision No. 317204
Decision date 18.06.2018
Funding period 01.09.2018 - 31.08.2022
Funding 559 080
Project description
Temperature is one of the most often measured physical quantities. Recent advances in primary thermometry has made the time ripe for a redefinition of the SI unit for temperature, the kelvin, by fixing the value of the Boltzmann constant (expected in 2018). This will enable primary thermometers to be built that do not have to compromise performance by operating well at both the triple point of water and at the temperature of interest. Instead, instruments can be designed that are dedicated for extremely accurate measurements at certain temperature intervals. It is the objective of this work to build such dedicated thermometers for extremely accurate measurements at selected temperatures. This will contribute to the current practice of thermometry using fixed point cells by lowering uncertainties, it will provide consistency checks to the defined value of the Boltzmann constant, and it will be a step in the direction of primary thermometry without fixed points and interpolation.