Temperature appears in the Calculation Data pane when many different models are selected. This field specifies the operating temperature in degrees C to use in the failure rate equation. Normally, the operating temperature is the ambient temperature of the surrounding air, but it can also be a board temperature, the temperature of the heat sink rails, or any other specified temperature.

While you can use any of these temperatures as the operating temperature, you should use the same type of temperature consistently. Operating temperatures are inherited and overridden in the same manner as model selections. For more information, see Model Selection.

You use Temperature delta in the Calculation Data pane to add a temperature adjustment value in degrees C to the operating temperature to get the ambient, environment, or case temperature, depending on which is appropriate for the model selected. While Temperature delta is unavailable for the top-most assembly (system), it is available for all lower-level assemblies.

For example, assume that you have a part and that in the Calculation Data pane for its parent assembly, 30 is entered for Temperature and 5 is entered for Temperature delta. The operating temperature of that part is 35, plus any junction temperature rise that may be specified for the part in its Prediction Data pane. For more information, see Prediction Data Pane.