The Rubotherm density measurement system allows highly accurate density measurements of fluids (liquids, vapours, supercritical gases) to be made. The system uses the Archimedes‘ principle, the acknowledged reference method to obtain the highest precision measurements of density. A sinker, whose volume is known, is weighed in the measuring fluid. The buoyancy that the sinker experiences is a measure for the density of the fluid. By using a Magnetic Suspension Balance this process can be applied in an extremely large pressure and temperature range to almost all substances with the utmost accuracy.
Density measurement of fluids with reference data quality is a precondition for formulating thermal equations of state. Highly accurate measurements of density are necessary for the calibration of industrial density sensors which for example are used in pipelines for accounting the supplied natural gas quantities.