THE STATUS OF THERMODYNAMIC THERMOMETRY

Since the International Temperature Scale of 1990 (ITS-90) was defined , there have been a number of significant developments in thermodynami c thermometry. New results have been published and further experiments are in progress or are planned. This special issue of Metrologia prov ides an appropriate occasion to review these developments. The new res ults show some differences between the ITS-90 and thermodynamic temper ature, but they are generally within one standard uncertainty of the v alues assigned in the ITS-90, Only in the region of 150 K have larger differences been reported, Further results must be awaited before firm conclusions regarding a new consensus for thermodynamic values can be drawn.