What would happen to the accuracy of a float gauge if the fluid it is

[jim1174]

What would happen to the accuracy of a float gauge if the fluid it is measuring is heated?

 

[Baluncore]

As the liquid expands and reduces it's density;
1. The level of the surface will rise significantly, inversely proportional to density.
2. The float will sink slightly deeper, but nowhere near enough to compensate for 1.

In addition to the temperature induced density change, the change in level reading will be dependent on the profile of the container and of the float.