Fred Sturm wrote: > On Dec 5, 2009, at 12:43 PM, Ron Nossaman wrote: > >> Fred, I still don't know what you're talking about. We've >> talked about break% for years and years and it's always >> been percentage of breaking tension at the string's >> current tension. How about posting the formula from your >> spreadsheet, as I did from mine, so I can see what you're >> doing? Ron N > > From the "Collins" spread for tension: > =((StringL*FreqP1*CoreDia)^2)*(CoreDens*PI())/(9.81*10^12)*(1+(IF(ISBLANK(CovDia),0,1))*((CovDens/10000)*(((CovDia^2)/(CoreDia^2))-1))) > > > > % break: > =IF($D$5="Röslau",100*L19/LOOKUP(F19,$AA$20:$AA$60,$AD$20:$AD$60),0)+IF($D$5="Pure > > > Sound",100*L19/LOOKUP(F19,$AA$20:$AA$60,$AC$20:$AC$60),0)+IF($D$5="Malcom > Rose C",100*L19/LOOKUP(F19,$AA$20:$AA$60,$AB$20:$AB$60),0) > > > > For the "Roberts/Rhodes" tension: > =(RC[-9]*RC[-8]/802.6)^2*2^((RC[-10]-(440-R11C2)/(440-415.3))/(6))*(RC[-6]*(RC[-7]^2/RC[-8]^2-1)+1) > % break =RC[-4]/(0.557*RC[-12]^1.667)*60 > > Which isn't exactly the formula, and if you can decipher > it, you are doing better than I am. The Roberts uses > inches, Collins is metric FWIW. Regards, Fred Sturm With none of the variables defined, it's useless. Ron N
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