Similar to the Heritage Screen for Random Vibration discussed in Section 4, the Heritage Thermal Screen would be one derived from past, successful, screening experience on equipment of comparable design and manufacture. Again, this should be an iterative process where the fallout, or flaw precipitation results, are carefully monitored so that screening strength can be adjusted to the most cost effective value as discussed in Method A.
A comparable approach to the Heritage Screen that is based on general thermal cycling results in the Baseline Thermal Screening profile given in Section 4. The Baseline approach is presented as a starting screen to be used when it is not possible to use Method A or no data are available for the Heritage screen. It is more important with the Baseline approach that the results be monitored and the screening strength be adjusted as necessary. Government approval is required for use of either the Heritage or the Baseline Thermal Screen