A derived field is a system calculated field with a value based on values in dependent fields. For example, PCS Axis calculates a value for the field Effective IR Correction based on values in the following dependent fields:
When a value for a dependent field has been updated in a data entry grid, a 
notification icon displays in the derived field indicating the value has changed and the data entry grid should be refreshed. Clicking the 
Refresh button updates all derived values and removes the notification icon (Figure 7-3).
notification icon displays in the derived field indicating the value has changed and the data entry grid should be refreshed. Clicking the Refresh button updates all derived values and removes the notification icon (Figure 7-3). 
Figure 7-3. Derived Field