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Join Date: May 2007
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Need to determine density via scan

05/13/2007 9:40 PM

Hi all

I'm very new to this area of technology, but I have a requirement to scan a solid object to determine its volume and hence derive its density. We know about some Ultrasound and Laser Technologies that exisit. Can anyone suggets another non-destructive approach, given that the samples will be up to 125 kg's It needs to be fairly robust device.

Thanks

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#1

Re: Need to determine density via scan

05/14/2007 4:00 AM

"...suggets another non-destructive approach..."

Archimedes: Dip it in a vessel rim-filled with non corrosive liquid, and calculate the displaced volume

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#2
In reply to #1

Re: Need to determine density via scan

05/14/2007 4:09 AM

Hi There

Thanks for the reply, I had thought of this but almost reckoned it was too simple, Should remember the old KISS principle I'm going to ask about this with our guys

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Active Contributor

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#3
In reply to #2

Re: Need to determine density via scan

05/14/2007 1:27 PM

Hello,

You may have already done this~or a reason why you haven't

Weight the part-
inport your scan into your CAD program this should automatically create
a solid file and the volume.

Then: Mass=Volume X Density

Good Luck,

:)Lisa

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#4
In reply to #1

Re: Need to determine density via scan

05/14/2007 11:33 PM

Eureka!! (sorry but someone had to say it!)

If you have scales capable of handling the mass you can place your container of liquid on the scales then lower the object in so that it is just immersed. The difference between the two readings will give you the exact volume, assuming you know the density of the liquid. Water makes it really easy if you can use it.

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#5

Re: Need to determine density via scan

05/15/2007 3:49 AM

Rediscover the Bushel +the weighbridge

<fairly robust device>?

YOU BET!

KISS

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Anonymous Poster
#6

Re: Need to determine density via scan

05/15/2007 6:42 AM

My first idea was the Archemedes approach. If you take the ratio of immersed weight Wi to dry weight Wd, you don't even have to calculate the volume or weigh liquid spilled over the top. Wd/Wi = (Density)/(Density-1).

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#7

Re: Need to determine density via scan

05/15/2007 8:38 PM

Hi Guys

I have to say I never thought I'd get such a quick response, I think the Archimedes way sounds good, please keep the msgs flowing (excuse the water pun :-) ) appreciate everyone taking the time to think about this

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#8
In reply to #7

Re: Need to determine density via scan

05/15/2007 10:49 PM

When you need to tap into the fountain of knowledge, you need to come to dis place...

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#9

Re: Need to determine density via scan

05/16/2007 12:00 AM

Hi All

One small complication just came out, the sample/object we're trying to measure, may have some form of porosity. So it can absorb water (darnit :-) ) So what's says the oracle now :-)

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#10
In reply to #9

Re: Need to determine density via scan

05/16/2007 12:18 AM

Dunk it in quickly. If you're using the displaced mass method you'll only need a few seconds to read off the weight.

If that won't work you might have to provide more information on the "object". What'll work for a block of wood might not work for a sponge.

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#11
In reply to #9

Re: Need to determine density via scan

05/16/2007 4:24 AM

Paint it.

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Anonymous Poster
#12
In reply to #9

Re: Need to determine density via scan

05/16/2007 1:10 PM

Can you put a plastic bag (garbage bag, leaf bag, etc.) around it, and dunk it in far enough so that the object is under water but the open top of the bag isn't?

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#13

Re: Need to determine density via scan

05/25/2007 12:42 AM

Ok one more thought, how about using Holgraphic imagining?

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Anonymous Poster (2); josephemm (4); Lisa Bilbrey (1); MUKULMAHANT (1); nutwood (3); Yuval (2)

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