So using your formula that makes Bev about 150 years old percent then, or
did I miss something.
Happy Friday.
Best regards
Mike
-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Lou Hart
Sent: Thursday, October 25, 2001 5:51 PM
To: [log in to unmask]
Subject: Re: [TN] Adjusting the alloy composition in the solderpot
Eric, Steve, et al,
I recommend going back to basic calculus and calculating the derivative of
fraction tin with respect to weight (mass) of tin.
Fraction tin = (Tin mass)/(Tin mass + Lead mass)
You will get (assuming you only want a small change in fraction tin, in the
range of, say, 0.03 or less)
Tin add = (Mass of pot) X (change desired in Fraction Tin)/(Fraction Lead)
On an unrelated matter, let me comment that a number of names like Shirley,
Beverly, and Vivian were used by men until the first half of the past
century. Over some time period, women largely took possession of them.
Lou Hart
-----Original Message-----
From: Eric Dawson [SMTP:[log in to unmask]]
Sent: Thursday, October 25, 2001 2:53 AM
To: [log in to unmask]
Subject: Re: [TN] Adjusting the alloy composition in the solderpot
Hi All,
The easiest way to think of this is not the use of a complicated formula,
but the simple application of percentage.
In the example below, the total weight of tin plus lead is 1500 pounds,
61.9% of which is tin. Hence there are 928.5 pounds of tin.
Add 45 pounds of tin, the total weight is now 1545 pounds of which, 973.5
pounds is tin. Work out the new percentage of the new total weight and you
get 63%.
Ahah, I hear you ask, how do you get to 45 pounds in the first place? Well,
just plug a few numbers into the percentage calculations and see which
direction it takes you.
The main thing to remember is that you add the tin addition to the total
weight as well as the tin content when working out the new percentage.
Hope this helps
Regards
Eric Dawson
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