Validation of the Thermal Diffusivity from Modified Monotonic Heating Regime Procedure

Problems of thermal diffusivity measurements when using monotonic heating regime methodology are discussed. A modification to a procedure applied to the specimen investigated at convective heat transfer conditions has been analyzed. Experiments are performed using two fluids of different thermal properties. By comparing the obtained data, it is possible to correct the negative effects of the finite Biot number. Results of test measurements performed on a PMMA cylindrical specimen are consistent with reference data, which demonstrates the reliability of the proposed modification. The suggested revisions in the measurement methodology have also been verified in the course of numerical simulations. It is concluded that high quality data can be obtained applying elementary experimental instrumentation and simple data processing.