1.1 This standard is one of a series of standards dealing with the sampling and testing of paints, varnishes and related products.
It specifies a test method for determining the specular gloss of paint films using a reflectometer geometry of 20°, 60° or 85°. The method is not applicable to the measurement of the gloss of metallic paints.
a) The 60° geometry is applicable to all paint films, but for very high gloss and near-matt films 20° or 85° may be more suitable.
b) The 20° geometry, which uses a smaller receptor aperture, is intended to give improved differentiation between high-gloss paint films (i.e. films with a 60° specular gloss higher than about 70 units).
c) The 85° geometry is intended to give improved differentiation between low-gloss paint films (i.e. films with a 60° specular gloss lower than about 10 units).
Note 1: The same geometry should, of course, be retained for a series of measurements even if this means disregarding the suggested limits.
Note 2: In some cases, the determination of specular gloss may not correspond to a visual assessment.
2 Normative References
The following normative document contains provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent edition of the normative document indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 3186-2006 Paints, Varnishes and Raw Materials for Paints and Varnishes — Sampling (ISO 15528:2000, IDT)
GB/T 13452.2 Paints and Varnishes — Determination of Film Thickness (GB/T 13452.2-1992, eqv ISO 2808:1974)
GB/T 20777-2006 Paints and Varnishes — Examination and Preparation of Samples for Testing (ISO 1513:1992, IDT)
