Step-wise transient method

The step-wise transient (SWT) method is an experimental technique for measuring the thermal diffusivity and conductivity of solid materials. A theoretical model, design of the experimental apparatus and sources of error are presented. Methods of experiment optimization and evaluation are illustrated by charts. The experiment is verified for polymethylmethacrylate (PMMA), yielding the thermal diffusivity 0.112 mm(2) s(-1) and thermal conductivity 0.197 W.m(-1) K-1 with the coefficient of variation around 0.7% for various values of input heat power and specimen thicknesses.