METHOD FOR MEASURING ABSOLUTE VALUE OF THERMAL CONDUCTIVITY

摘要

A method of measuring the absolute value of thermal conductivity of low thermal conducting solid materials. Thermal conductivity and heat capacity of the sample are determined simultaneously in a single measurement with the prerequisite that these values are frequency independent. This method is realized on power-compensated differential scanning calorimeters "DSC" without any modification in the measuring system. The DSC (3) consists of a sample (1), which is preferably in disk formation, and a grease layer (2). The DSC is calibrated in a standard way for temperature and heat flow. The method uses temperature-time profiles consisting of one fast temperature jump of 0.5 to 2 K and an isotherm. The measuring time for each temperature is less than 1 minute. For input parameters, only sample thickness and contact area with the DSC furnace, or sample diameter if the sample is disk shaped, are needed together with sample mass. In addition to the sample thermal conductivity and heat capacity, the effective thermal contact between sample and the DSC furnace is determined.