Mathematic modeling of a new inlay buoyancy artefact


  • K. Lehrmann Physikalisch-Technische Bundesanstalt Braunschweig
  • F. Härtig Physikalisch-Technische Bundesanstalt Braunschweig
  • R. Tutsch Technical University Braunschweig Institute of Production Metrology Braunschweig



The novel buoyancy artefact concept for the use in mass metrology enables the determination and correction of systematic air buoyancy effects caused by measurements outside a vacuum. In contrast to other buoyancy artefacts with a nominal mass of 1 kg, the new artefact, called inlay artefact, has a smaller volume resulting from an enclosed tungsten core. The theoretical design of the new artefact consists of dismountable discs with spherical distance pieces and a cylinder. This work focuses on the design and mathematical model considering limiting factors caused by the handling and the geometry of the comparators used.