Deleted
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Member since January 1970
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Post by Deleted on Aug 21, 2012 13:23:05 GMT -5
By the way, I found this in a book. Does anyone find things in books anymore? Ok, five seconds has gone by and no answer so I guess I am the only one. jeez, I need to get a life. lol Jim
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Post by jakesrocks on Aug 21, 2012 13:23:48 GMT -5
Nah, I'll pass. Algebra was my weak point in school.
Used to torque the math teachers jaws on regular math tests though. He made everyone turn in their work sheets with their tests. Mine always went back blank. I solved them in my head and didn't need a work sheet. Of course he thought I was cheating. Made me stay after school to re take the test. With him watching my every move, I took the test and aced it without using my work sheet.
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Post by Bluesky78987 on Aug 21, 2012 13:24:49 GMT -5
I think we should have a contest for how many different methods people can come up with!
There was one picture when I googled SG of a full pitcher, then a rock dropped in it, and the overflow directed into a separate container for weighing. That one seems doable.
You're right that accurately measuring volume is a little tricky. But if you only need to be within 0.1 on the SG, I calculated that you only need to be within about . . . dang what was it . . . 50ml on a 1 pound rock. Or something like that. I'd have to look at it again. I'm getting old, can't remember anything anymore!
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Post by Bluesky78987 on Aug 21, 2012 13:25:59 GMT -5
Oh that's awesome Don! I can't do anything in my head, I always have to scribble down little notes everywhere, even if I'm dividing 100 by 10!
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meta99
has rocks in the head
Ohio Flint Ridge flint
Member since October 2010
Posts: 540
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Post by meta99 on Aug 21, 2012 17:08:17 GMT -5
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itsandbits
freely admits to licking rocks
Member since March 2012
Posts: 825
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Post by itsandbits on Aug 21, 2012 19:01:17 GMT -5
Ok, I have a question for you guys. Could you just (a) weigh the rock dry (get grams), (b) calculate it's volume by dropping it in a bucket and seeing how much the water rises (get mililiters), (c) divide? If you do it in grams and mililiters, you don't even have to divide by the SG of water becuase the SG of water is 1 gram/ml. All this weighing of the water thing seems more complicated to me rather than less. But maybe I'm missing something? You're still dunking in water, and then having to do calculations too When Jim started this I posted another version of the same thing that makes it real easy for the apartment /kitchen type setup; it's about 8-10 posts from the top of the first page. I us eit all the time and it takes seconds for each stone. The limiting factor is the digital scale I have only goes to 10kg but larger ones are readily available; this one costs 15$ and is very accurate.
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Post by Bluesky78987 on Aug 22, 2012 10:15:53 GMT -5
Yeah, and as somebody (you?) mentioned, measuring volume of water accuratly requires a tool that I don't currently have. ;-) Will look at your setup, itsandbits, thanks.
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Deleted
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Post by Deleted on Aug 28, 2012 17:54:38 GMT -5
Yeah, and as somebody (you?) mentioned, measuring volume of water accuratly requires a tool that I don't currently have. ;-) Will look at your setup, itsandbits, thanks. In an SG test measuring the water, beyond weighing what it is you have, is not necessary. Further, if you did want to have an exact volume of water, then weight it. At 1 gram per milliliter, measure a volume in grams, and convert that to milliters or ounces, your choice.
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