Density is an important factor when it comes to plastic parts due to how it effects the material properties. The bulk density of solid parts can be determined by adding specimen into liquid density gradients. This technique can also be used for other materials besides plastics.
This standard is used to determine the densities of plastics through observing how far in a liquid filled column the center of mass of a specimen will sink. Liquids in the column have known densities and the part density is calculated based on these densities.