ISO 8130-2:2021 Coating powders — Part 2: Determination of density by gas comparison pycnometer (referee method)

ISO 8130-2:2021 Coating powders — Part 2: Determination of density by gas comparison pycnometer (referee method). I Scope This document specifies a method for the determination of density for all types of coating powders using a gas comparison pycnometer. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 813044, Coating powders — Part 14: Vocabulary ISO 15528, Paints, varnishes and raw materials for paints and varnishes — Sampling 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 8130-14 apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — ISO Online browsing platform: available at https://www.iso.org/obp — I EC Electropedia: available at http://www.electropedia.org/ 4 Principle The density is calculated from the mass and the volume of the test portion. The volume of a weighed test portion is determined by measuring the volume of gas displaced within a receptacle when the test portion is introduced. This is achieved by measuring the pressure difference which arises due to the displacement of the gas. 5 Materials 5.1 Helium or nitrogen, minimum Grade 4,8, in a steel cylinder. Other high purity gases may be used provided that the product under test is not affected and this deviation from the method is noted in the test report. 6 Apparatus Ordinary laboratory apparatus, together with a gas comparison pycnometer for the automatic or manual determination of density. The measured pressure difference shall not be greater than 1 %. For manual pycnometers, the swept volumes of the cylinders measured should be equal to or within 0,5 % (relative). Weigh the sample container to the nearest 1 mg and fill it with the product under test, making sure that no powder is on the outside walls of the container. Weigh the container plus contents to the nearest 1 mg to determine the mass (m) of the test portion. Place the container and contents in the apparatus and determine the volume of the test portion. Repeat the volume measurement in order to ensure that the reading is consistent and calculate the mean (V) of the two volumes. NOTE Depending on the grade of gas,...