Verituner help

[Phil Ryan]

The guys in the local chapter have asked me to bring my Verituner for 
show-and-tell  to the next chapter meeting(Tuesday), so I've been 
reading through the manual and come up with a little confusion that I 
hope someone will clarify, namely, Overpull percentages.

The machine lists as default three percentages 10 (wound strings); 30 
(plainwire); and  36% (treble) or all.  I know you can change these and 
turn them on and off as you progress up/down the piano. 

My questions are, how does the piano know which strings are wound and 
not?  If you highlight them "all",  does the piano change them as you 
tune up or down?  The default percentages also confuse me as I have 
rarely, if ever, found 10 % to be appropriate (common ) for a bass pitch 
raise and 30% seems to be a little high for a default percentage for 
midrage notes.  Can anyone shine a little light on this?  Thanks.

Phil Ryan