Discussion:
Weighing Hot Objects
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Segun Fawole
2020-11-11 07:30:42 UTC
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How can one get the actual weight of a hot object? Is there a mathematical or any expression that helps to correct for the convection caused by hot air?
Dean
2020-11-11 12:35:17 UTC
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Post by Segun Fawole
How can one get the actual weight of a hot object? Is there a mathematical or any expression that helps to correct for the convection caused by hot air?
You must simply weigh it in a vacuum.
micky
2020-11-15 03:26:04 UTC
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In sci.chem, on Tue, 10 Nov 2020 23:30:42 -0800 (PST), Segun Fawole
Post by Segun Fawole
How can one get the actual weight of a hot object? Is there a mathematical or any expression that helps to correct for the convection caused by hot air?
Is it floating too? You can't put it on a scale, OR you think that its
heat make it seem to weigh less than it really does, even if it's
sitting on a scale? Which?
mrou...@shaw.ca
2020-11-15 16:40:14 UTC
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Post by Segun Fawole
How can one get the actual weight of a hot object? Is there a mathematical or any expression that helps to correct for the convection caused by hot air?
Short answer: suppress convection by putting the hot object inside a closed box (which was weighed ahead of time). You would still have to worry about buoyancy corrections, but that's an easier problem.

In a quick (not thorough) search, I found the following: https://www.sciencedirect.com/science/article/abs/pii/0040603186800107

The authors of this paper suggest that convection can create errors in weighing of the order of micrograms. Of course, that would depend on many, many details. I don't think there is any hope of applying a simple formula to calculate a correction. Avoiding the issue by suppressing convection is still your best bet.
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