Prior to running a simulation the user must first specify properties data for the specimen and jaw materials used, in the Material Properties Database. Electrical resistivity, specific heat capacity, thermal conductivity and density can all be specified as a function of temperature. When testing above the solidus temperature is performed, the latent heat of fusion and fraction solid versus temperature can also be specified.

After specifying the temperature-time program to be followed at the central control thermocouple location during the test the simulator is used to predict the evolution of temperature with time throughout the specimen and jaws. The applied voltage is adjusted at regular intervals enabling the simulation to closely follow the time-temperature program. The applied voltage is used to predict the distribution of current densities throughout the specimen and jaws. A powerful finite difference algorithm then calculates the I2R effect and the conduction of heat along temperature gradients in three dimensions. The loss of heat from surfaces and the transfer of heat across the specimen/jaw interface is controlled by two separate heat transfer coefficients specified by the user.