New methods to determine a comprehensive and low-uncertainty temperature dataset
In 2018, the kelvin – the SI base unit of temperature – will be redefined in terms of the fundamental Boltzmann constant, as part of the international effort to make a logical, coherent and complete system of units for the foreseeable future. To guarantee a successful transition, the redefinition must be founded on robust primary thermometry methods and results. In particular, a robust dataset is required that details deviations between temperatures founded on the current rather than the new kelvin definition. This project has built upon the achievements of the preceding EMRP project SIB01 InK by extending the capabilities developed into areas previously unexplored, such as ultralow temperatures in the range of 0.0009 K to 1 K. The new methods and data developed have completed the remaining gaps in knowledge required to establish a comprehensive low-uncertainty dataset, ensuring the definition is achieved and disseminated effectively.