ASTM D792 Test Standard for Density and Specific Gravity (Relative Density) of Plastics by Displacement

EUROLAB laboratory provides testing and compliance services within the scope of ASTM D792 standard. The ASTM D792 standard defines the determination of the specific gravity (relative density) and density of solid plastics in forms such as sheets, rods, tubes, or molded parts. Two test methods are described: A for testing solid plastics in water and B for testing solid plastics in liquids other than water.

Density is the mass per unit volume of a material. Specific gravity is a measure of the ratio of the mass of a given volume of material to the same volume of deionized water at 23°C. Specific gravity and density are particularly important because plastic is sold on a cost-per-pound basis, and lower density or specific gravity means more material per pound or miscellaneous part weight.

There are two basic testing procedures: Method A and Method B. The more common method is Method A, it can be used with sheet, bar, pipe and molded products. For Method A, the sample is weighed in air, then when immersed in distilled water at 23°C, using a sinker and wire to keep the sample fully submerged as required. Density and Specific Gravity are calculated.

This standard test method allows measuring the density and specific gravity of plastic materials by buoyancy in a liquid such as water. The principle of the test is easy to understand, but the method offers several sources for measurement errors such as submerged specimen fixation, air bubbles and others. Some balance manufacturers offer specific fixtures as well as advanced methods that increase accuracy.

An average density is calculated using these test methods, as different parts of a sample are likely to differ in density due to differences in crystallinity, thermal history, porosity, and composition (types of resin, plasticizers, fillers, etc.).

Values ​​stated in SI units should be accepted as standard.

This standard does not purport to address all, if any, security issues associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices prior to use and to determine the applicability of regulatory restrictions.

Our organization, EUROLAB, provides test standard services for the density and specific gravity (relative density) of plastics with displacement, within the framework of national and international standards, with its trained and expert staff and advanced technological equipment, among numerous test, measurement, analysis and evaluation studies. Provides testing services within the scope of ASTM D792 standard.