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.