Calorific Power of a Heating Element and Its Application to Measure Thermal Conductivities

This paper aims to determine the calorific power of a heating source and to establish an experimental
procedure to measure heat transmission coefficients in low heat conductive materials. In our case, the
source is a laterally isolated aluminum cylinder, which incorporates an internal electrical resistance for
controlling the heat, adjusted to a preset temperature. We describe a simple model, based on the
resolution of the differential equation for the heat balance, incorporating two gain and loss coefficients
and its application to the steady response achieved, when a disk shaped plastic sample is placed
between the heating element and a glass vessel with water, treating the set as a composite wall. In
this way the calorific power values and the thermal conductivities of the plastic disk sample are
obtained for temperatures ranging from 30 to 70°C.