fac question

[Wimblees@AOL.COM]

At the PNW seminar in Provo, Dr.  Sanderson told us we can use FAC number 
established by one Acutuner, and transfer them to another Acutuner, and have 
the FAC number work. 

I have also been told that on a pitch raise, we should not use the FAC 
numbers to do a regular tuning, that we established for the pitch raise.

Now the questions.  At what point is can we transfer, or use the same FAC 
numbers? What would be considered a pitch raise that would require a 
recalculation of the FAC?