Apparatus to measure volume

saplingg

Could anyone recommend a piece of lab apparatus which will measure the volume of an irregular object? I cannot use displacement of water as the object will compress under pressure and I suspect submerging the object in water will give a different displacement from the actual volume at 1 atm.

Ideally I would use something that could measure volume optically... Anybody know of an apparatus which does that?

berkeman

If you know its density, you could just weigh it.

Otherwise, you could use a 3-D digitizing device to digitize its outline. I've seen them in the past, but will have to do a quick search to see if I can find one. It's like a wand mounted on an articulated arm with rotary and linear encoders to pick up where the tip of the wand is.

I don't think you'll be able to do it optically in the general case. If your object is always convex, then you could probably do it optically with a laser grid projected on the object, and a TV camera picking up the image as you rotate it.

berkeman

Wow, I just did a google search on 3D Digitizer, and got a bzillion hits. Here's one:

http://3ddigitalcorp.com/escan.htm

They do it optically. And here's an article about doing it with a wand:

http://lear.inrialpes.fr/people/trig...os/aritaki.pdf

saplingg

Thanks alot! that's just what i needed.