ATPL question

[General Mutley]

regarding a float type fuel gauge. Surely atmospheric pressure would affect the reading as the volume of the liquid would change with higher/lower pressure depending on altitude?
It does'nt appear as a factor in any of the lists in my reference material but it did pop up on a CAA exam.
Any thoughts please - thanks

[Keith.Williams.]

Remember that liquids are effectively incompressible.

So the changes in pressure that are caused by changes in altitude will not change the volume of liquid fuel.

[General Mutley]

thankyou