View of the Magnetic Floatation Equipment (IMAGE) Physikalisch-Technische Bundesanstalt (PTB) Caption The sinker lies on a holder whose weight is compensated by the buoyancy of a hollow sphere and of an adjusting weight. Credit PTB Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.