The method measuring thermal conductivity of powders and solids with thermistor probe

摘要

A thermistor probe method is developed for measuring the thermal conductivity of buffer materials used in the repository of high level radioactive wastes. The two-dimensional heat conduction model including a thermistor probe is developed and calculated with a numerical method. Thermal conductivity is determined so as to minimize the differences between the numerical and measured temperature histories. The thermistor is calibrated using an aqueous solution of 0.5 wt % gelatin as a standard material. For the confirmation of the validity of the model, the thermal conductivity of glycerol and mercury is measured and compared with their reference values. The measured thermal conductivity of bentonite shows a good agreement with the recently reported values.