Open AccessThe thermal and electrical conductivities of several metals between — 183° C. and 100° C
Publication year - 1933
Publication title -
proceedings of the royal society of london. series a, containing papers of a mathematical and physical character
Language(s) - English
Resource type - Journals
eISSN - 2053-9150
pISSN - 0950-1207
DOI - 10.1098/rspa.1933.0109
Subject(s) - thermal conductivity , tube (container) , materials science , electrical resistivity and conductivity , thermal conduction , thermal resistance , work (physics) , thermal , electrical resistance and conductance , electrical conductor , axial symmetry , glass tube , composite material , current (fluid) , metal , mechanics , thermodynamics , electrical engineering , metallurgy , structural engineering , physics , engineering
In a previous paper an electrical method of determining the thermal conductivity of metals in wire form was described. The apparatus was of a simple kind, the wire being soldered axially in a glass tube with metal end-pieces. By maintaining a vacuum of the order of 10-4 mm. Hg in the tube, the heat developed in the wire on passing a steady current through it is conducted along it and through its ends except for a small amount lost laterally to the walls of the tube by molecular conduction and by radiation. The thermal conductivity of the wire is calculated from its known dimensions, the rate at which electrical energy is supplied to it, and the change in its electrical resistance. A small correction is applied to allow for the lateral loss of heat. The method has a number of advantages:— (1) The apparatus used meets the requirements of theory almost exactly and it permits the use of wires of any diameter. (2) The direct determination of temperatures is not required, as they are in effect obtained by measuring changes in the resistance of the wire. (3) The method lends itself particularly to low temperature work. (4) The electrical conductivity is obtained from observations which are also used in determining the thermal conductivity, so that both are obtained under the same conditions.