4. Heat dissipation measurement systems

4.1 Method principle

A heating element dissipates its energy differently depending on the nature or phase of the medium in which it is immersed, as the surface heat transfer coefficient is not the same. In the case of a solid-liquid interface, the latter is relatively good. It includes transfers by conduction and natural convection (calm medium), or by forced convection (stirring, agitation). The solid-gas and solid-vapor transfer coefficients, on the other hand, are much poorer.

When a given amount of energy is injected into a probe, for example by passing a current of known intensity through a given resistor, the probe's temperature will rise relative to the medium as the latter becomes more difficult to dissipate the heat produced, particularly when the...