A dual-thermistor probe for absolute measurement of thermal diffusivity and thermal conductivity by the heat pulse method

Based on a transient thermal model of a point heat pulse, a dual-thermistor probe, in which two thermistor beads serve as point heater and temperature sensor respectively, has been developed for absolute measurement of thermal diffusivity and conductivity. An experimental system with high sensitivity for temperature change is designed to perform the measurement. Experimental results of samples are in agreement with the recommended values. The validation of the one-dimensional point source heat transfer is discussed, and the deviation from the theoretical model is negligibly small for the measurement. The estimated measurement uncertainties are 3.5% and 5.3% for thermal diffusivity and conductivity respectively.