Summary of achievements of the European Metrology Research Programme Project “Implementing the new Kelvin” (InK 1)

We report a summary of the technical achievements of the European Metrology Research Programme Project (EMRP) “Implementing the new Kelvin” (InK 1). In short these are:•The first determination of definitive thermodynamic temperatures for the point of inflection of the high temperature fixed points of Re-C, Pt-C and Co-C as well as a new evaluation of the Cu freezing point.•The first trial of the new dissemination mechanisms for thermodynamic temperature at high temperatures, as described in the mise en pratique for the definition of the kelvin (MeP-K).•A new ultra-low uncertainty thermodynamic evaluation of T − T90 from about 30 K to 303 K, with particular emphasis on temperatures around the water triple point (273.16 K).•The first re-evaluation of T − T2000 from 0.02 K to about 1 K with an uncertainty of <1%.Taken together these results represent a significant advance in primary thermometry. We also give a brief introduction to the successor project (InK 2) and discuss the impact of this work on the kelvin redefinition and next version of the MeP-K (i.e. the MeP-K-19).