dc-ac hot-wire procedure for determining thermophysical properties under pressure

Abstract
The paper describes a new hot-wire method for simultaneous determination of thermal conductivity and heat capacity per unit volume of electrically insulating liquids and solids under pressure. The method uses dc heating of the hot wire, whereas the temperature increase is recorded by an ac bridge circuit. The temperature data obtained are analyzed using the exact solution instead of the commonly used long time approximation. The procedure was tested on a number of alcohols and water and the accuracy was found to be 1.5%. New data on glycerol up to 1.5 GPa are presented. The appearance of an automagnetoresistance effect when Ni is employed as hot-wire probe is discussed.