Determination of Density

The determination of the density of liquids and solids is done using the Pycnometer method or by the buoyancy method employing Archimedes principle.

RIO GmbH tests, among others, in accordance with DIN EN ISO 1183, 23811, 2811, 3369.

In the buoyancy method a body that is completely immersed in a liquid develops a buoyancy that is the same as the weight of the volume of the displaced liquid.


In the Pycnometer method a so-called Pycnometer (a glass vessel with a ground stopper that has a capillary hole) is weighed several times. One weighing determines the empty weight, a second weighing the weight of the standard liquid (usually water at 20°C), and a third weighing determines the weight of the liquid to be measured and the sample with the standard liquid. It is necessary to work carefully when using this method, as is also the case with the buoyancy method, since temperature changes and air bubbles can affect the result.