This part of ISO 1183 specifies three methods for the determination of the density of non-cellular plastics in the form of void-free moulded or extruded objects, as well as powders, flakes and granules. — Method A: Immersion method, for solid plastics (except for powders) in void-free form. — Method B: Liquid pyknometer method, for particles, powders, flakes, granules or small pieces of finished parts. — Method C: Titration method, for plastics in any void-free form. NOTE This part of ISO 1183 is applicable to pellets as long as they are void-free. Density is frequently used to follow variations in physical structure or composition of plastic materials. Density might also be useful in assessing the uniformity of samples or specimens. Often, the density of plastic materials will depend upon the choice of specimen preparation method. When this is the case, precise details of the specimen preparation method will have to be included in the appropriate material specification. This note is applicable to all three methods.