THE MELTING-POINT OF GALLIUM UNDER CALORIMETRIC CONDITIONS

The International Temperature Scale of 1990 (ITS-90) is the latest of six temperature scales adopted by the Commite International des Poids et Mesures (CIPM) and the only one recommended for current use. It is defined by assigning a precise temperature value to 17 fixed points an d the election of the interpolating instruments and equations. One of these fixed points is the gallium melting point (302.4196 K). This poi nt, if used correctly, could help to elucidate problems associated wit h the reproduction of other fixed points. In this paper we describe an apparatus used for the reproduction of this point under calorimetric conditions. The plateaus obtained in the result are compared with thos e obtained using a traditional method. The reproducibility and repeati bility of this fixed point using this apparatus are also discussed.