An Intercomparison of Temperature Scales in the Range 1 to 30 K Using Germanium Resistance Thermometry

Abstract

The current temperature scales for the region 1.1 to 30 K have been intercompared by means of 31 germanium resistance thermometers originating from eight national laboratories. The scales compared include the International Practical Temperature Scale of 1968, the helium vapour pressure scales and various national scales based on gas, acoustic and magnetic susceptibility thermometry. While the overall scatter between these scales is some 15 mK, the intercomparison reveals agreement of the order of 1 mK between the most recent scales based on magnetic susceptibility measurements and using common fixed points. The values of the superconductive transition temperatures of aluminium, indium and lead on each of the scales have been determined.