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  • Weighing Hot Objects

    From Segun Fawole@21:1/5 to All on Tue Nov 10 23:30:42 2020
    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?

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  • From Dean@21:1/5 to Segun Fawole on Wed Nov 11 04:35:17 2020
    On Wednesday, November 11, 2020 at 2:30:44 AM UTC-5, Segun Fawole wrote:
    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.

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  • From micky@21:1/5 to segunfawole11@gmail.com on Sat Nov 14 22:26:04 2020
    In sci.chem, on Tue, 10 Nov 2020 23:30:42 -0800 (PST), Segun Fawole <segunfawole11@gmail.com> wrote:

    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?

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  • From mroussel@shaw.ca@21:1/5 to Segun Fawole on Sun Nov 15 08:40:14 2020
    On Wednesday, November 11, 2020 at 12:30:44 AM UTC-7, Segun Fawole wrote:
    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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