Relative measurements of thermal conductivity of liquid gallium by the transient hot-wire method

Thermal conductivity of liquid gallium as a function of temperature has been determined by the transient hot-wire method with an alumina-coated probe. Theoretical analysis of the temperature increase of the hot wire with coating indicates that the coating layer affects absolute measurements by this method and its presence is prone to yield smaller values of thermal conductivity. Relative measurements were carried out over the temperature range 310-471 K on liquid mercury and gallium at 310K as standard samples to establish the correction line. The thermal conductivities obtained for liquid gallium are as follows: 29.3 W m - 1 K - 1 at 338 K, 30.5 W m - 1 K - 1 at 379 K, and 31.8 W m - 1 K - 1 at 471 K. These values are greater than those derived from absolute measurements but smaller than the values predicted from the Wiedemann-Franz law and smaller than several reported values.