This International Standard specifies two test methods for determining the density of compact vulcanized rubbers. These determinations have a certain importance in controlling the quality of a rubber-based mixture and in calculating the mass of rubber necessary to obtain a given volume of vulcanizate. This International Standard does not concern the determination of the relative density of rubbers, which is the ratio of the mass of a given volume to the mass of an equal volume of pure water at a given temperature. In this International Standard, the determination is made by measuring the resulting gravitational forces under different conditions, but, for convenience, these forces are expressed in units of mass.