Equally artefacts are as opposed in vacuum and in air. By evaluating the two artefacts of equivalent nominal weight, the massive quantity variation demonstrates the air buoyancy and therefore leads to a very exact perseverance of air density. The buoyancy artefacts are generally used for the M_one vacuum mass comparator. https://bailing-wire57889.blogsumer.com/30354179/an-unbiased-view-of-bailing-wire