A simple device for determining thermal effusivity of thin plates

We measured thermal effusivity of thin plates in the longitudinal direction. This parameter is strongly correlated with lateral convection, so its determination is very difficult. Thermal quadrupole theory is presented which allows the theoretical expression of the problem to be determined. By applying a heat flux without a low-frequency component, only some characteristic times of the system are excited. A real-time method of estimation is developed by using a non-integer derivative signal. The results obtained for a copper plate are in good agreement with the literature.