to improve techniques for the realization of defining fixed points and for interpolating instruments;

to study non-uniqueness and the thermophysical properties of fixed points;

to update the Supplementary Information for the ITS-90;

to maintain the mise en pratique for the definition of the kelvin; and

to assess needs and formulate plans for the next International Temperature Scale.

Working Group 1 is tasked to continue with the updates to the Supplementary Information for the ITS-90, collaborating with Working Group 3 and Working Group 5 in the incorporation of material on uncertainties, to coordinate a task group (including a representative from Working Groups 3, 4, and 5) formulating an assessment and possible work plan for the next International Temperature Scale and to prepare and maintain the mise en pratique for the definition of the kelvin.