A step-wise method for measuring thermophysical parameters of materials

A version of a transient method for measuring specific heat, thermal diffus ivity and thermal conductivity is presented. The dynamic temperature held i s generated by the passage of the electrical current through a planar elect rical resistance made of thin metallic foil. The heat is produced in the fo rm of a step-wise function. A thermocouple placed apart from the heat sourc e measures the temperature response. The theory of the method, its experime ntal arrangement and the measuring regime for considering sensitivity coeff icients art: presented. Experimental data obtained on Perspex are compared with recommended and published data. The data on thermal conductivity agree to within +/-0.7% whereas the specific heat is lower on average by 5.2% an d the thermal diffusivity is higher by 3.5% when measurements were realized in vacuum. A shift in data of up to 10% was found for measurements made in air.