【国外标准】 Standard Test Method for Density of Plastics by the Density-Gradient Technique

4.1 The density of a solid is a conveniently measurable property which is frequently useful as a means of following physical changes in a sample, as an indication of uniformity among samples, and a means of identification.4.2 This test method is designed to yield results accurate to better than 0.05 %.NOTE 3: Where accuracy of 0.05 % or better is desired, the gradient tube shall be constructed so that vertical distances of 1 mm shall represent density differences no greater than 0.0001 g/cm.3 The sensitivity of the column is then 0.0001 g/cm3·mm. Where less accuracy is needed, the gradient tube shall be constructed to any required sensitivity.1.1 This test method covers the determination of the density of solid plastics.1.2 This test method is based on observing the level to which a test specimen sinks in a liquid column exhibiting a density gradient, in comparison with standards of known density.NOTE 1: This test method is equivalent to ISO 1183-2.1.3 The values stated in SI units are to be regarded as the standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.