Abstract. A revised table of differences (t₉₀ - t₆₈) between values of temperature on the International Temperature Scale of 1990, ITS-90, and the corresponding values on the International Practical Temperature Scale of 1968, IPTS-68, is published at the request of the Comité Consultatif de Thermométrie (CCT). The revision affects only the range 630°C to 1064°C, where the IPTS-68 specified the use of platinum-10% rhodium versus platinum thermocouples. It follows from new intercomparisons of thermocouples carrying IPTS-68 calibrations with platinum resistance thermometers and radiation thermometers calibrated in accordance with the ITS-90. The largest change occurs at 760°C, where the difference formerly tabulated as 0,36°C is now 0,04°C. The revision concerns only the assessment of the differences between the ITS-90 and the IPTS-68, and does not affect the ITS-90 in any way.

Print publication: Issue 2 (1994)
Received 25 April 1994