In mass determination on a high accuracy level the effect of buoyancy through the ambient air has a big impact and so has to be taken into consideration. That is why in a mass laboratory a very accurate equipment to measure the air density with an uncertainty down to 10~(-5) is necessary. This must of course be a metrologically approved system and a set up which is convenient in use too. For example for the transition from the national 1 kg platinum iridium artefact to the national 1 kg stainless steel main standard and for the mass determination of solid density standards an alternative to the parameter method is needed. A pair of air buoyancy artefacts have been designed one hollow and one massive one which may be used simultaneously during the mass comparison process. It also may reduce additional measuring efforts considerably as the principle is based on one of the fundamental methods. The buoyancy artefacts are of stainless steel and can be treated and handled in the same manner as normal highly precise mass standards.
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