if we weigh a metal object which is immersed in water, we have to correct the buoyant force for water. Air is a fluid. Why don't we correct for the buoyant force of the air when we weigh it in the air? What i think it may be is because we have a set atmospheric pressure being 1.013 Kpa in the air and we measure everything in relation to the world relative to that? Can someone discuss why this is, I'm not sure what i said onto is a logical quick explanation, but there should be much more to this?