Dynamic technique for measuring thermal conductivity in cylindrical geometry

摘要

A dynamic technique for measuring thermal conductivity in cylindrical geometry is presented. A radially centered heater wire is used. The temperature difference between two different radial positions in the cylindrical specimen is monitored during heating. Measurements are made under vacuum and within a thermal shield to minimize heat losses. Bulk‐specimen temperature rise is restricted to 1/2 °K. For a specified time interval, which is a function of specimen dimensions and thermal properties, the measured temperature difference is constant to within a fraction of 1% and is inversely proportional to the thermal conductivity of the specimen. The thermal diffusivity and heat capacity are not specifically needed to determine the thermal conductivity. Mathematical development of the theory of the technique is presented along with the results of measurements on single‐crystal silicon and aluminum specimens.