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Simple Specific Gravity tester

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Phil

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Sep 22, 2008, 7:08:07 PM9/22/08
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I saw a writeup in CW, NN, or WCN on a simple $10 device to measure specific
gravity using an electronic scale. I misplaced the article. Anyone have the
information? Thanks

Phil


Jeff R.

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Sep 23, 2008, 5:32:04 AM9/23/08
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http://mendosus.com/sg.html

--
Jeff R.

Andy

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Sep 23, 2008, 7:46:44 AM9/23/08
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"Jeff R." <conta...@this.ng> wrote in message
news:48d8b797$0$31800$afc3...@news.optusnet.com.au...

Wow, thats awsome! You know, I've got a science degree and been a science
teacher for 2 year now and I had never learnt how to measure SG, I suppose I
was never in the right place at the right time to learn it. It also seems
like its just as easy to measure the density of something as long as you
know the density of water at the temperature and pressure you're using.
I might try making an experiment for my students where they can calculate
the SG's of a few things. What would be cool is if I could find a fake
silver coin, they could try and work out which of 2 coins is real. Of
course all the real silver coins I have are 90% at best but could still be
an interesting experiment. Anyone have some fakes in Australia that they'd
like to get rid of?
Andy


Jeff R.

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Sep 23, 2008, 8:21:28 AM9/23/08
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Andy wrote:
>... Anyone have some fakes

> in Australia that they'd like to get rid of?
> Andy

May I send you one M.Turnbull?

More sensibly - may I suggest you do a comparison between a pre'46 Aussie
florin and a post-'46.

The pre is Sterling (92.5%) and the post is 50%.
Should be a piece of cake to detect - even for school kids.

Easy to source the coins, too.

--
Jeff R.

Bruce Remick

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Sep 23, 2008, 3:00:50 PM9/23/08
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"Andy" <Imsick...@imsickof.spam> wrote in message
news:EG4Ck.158$sc2...@news-server.bigpond.net.au...

When you're doing the teaching, don't forget to explain to your students any
practical reasons for determining the specific gravity of something. I
always had a "why would anyone ever need to know that?" feeling with many of
my high school science and physics experiments.


Andy

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Sep 23, 2008, 6:19:44 PM9/23/08
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"Bruce Remick" <rem...@cox.net> wrote in message
news:qybCk.41413$PK.2...@newsfe04.iad...
Good thinking Jeff, I'll do that. Yes, thats the whole idea of the
experiment, to give some relevance to the things they're learning. Pitty
gold is so expensive, it would be good to make a gold crown (head piece, not
the coin) and compare it to a non-gold one.
Thanks,
Andrew


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