The promise of platinum as a high temperature thermal conductivity reference material

The thermal conductivity of platinum has been determined over the range 0 to 950° C and found to remain constant to within 0.5% of the value 0.73 w cm -1 degC -1 . This is one of several reasons for regarding platinum as a promising thermal conductivity standard, or reference material, for use in that range and possibly to higher temperatures. The work would appear to require independent confirmation since the values at the maximum temperature are about 20% lower than four out of the five previous determinations. Support is, however, forthcoming from the behaviour of the Lorenz function which decreases from 2.7 × 10 -8 to 2.5 × 10 -8 v 2 degK -2 as the temperature increases from 100 to 925° C.