ISO 4628-1:2016 pdf free
ISO 4628-1:2016 pdf free.Paints and varnishes一Evaluation of degradation of coatings
This part of ISO 4628 defines a system for designating the quantity and size of defects and the intensity of changes in appearance of coatings and outlines the general principles of the system used throughout ISO 4628. This system is intended to be used, in particular, for defects caused by ageing and weathering, and for uniform changes, for example yellowing.
The other parts of ISo 4628 provide pictorial standards or other means for evaluating particular types of defect. As far as possible, already existing evaluation schemes have been used as the basis.
This part of ISO 4628 is also used for asessing defects not covered by the other parts of ISO 4628.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 13076, Paints and varnishes一Lighting and procedure for visual asessments of coatings
3 General principles of the system
A uniform convention has been adopted for designating the quantity and size of defects and the intensity of changes by means of ratings on a numerical scale ranging from 0 to 5, 0 denoting no defects or changes, and 5 denoting defects or changes so severe that further discrimination is not reasonable.
The other ratings, corresponding to the numbers 1, 2, 3, and 4, are so defined that they give optimum discrimination over the whole range of the scale.
The use of intermediate half-steps is permissible, if specified, to give a more detailed report on the defects or changes observed.
NOTE 1 The quantity of small defects scattered over the test area may be assessed by means of a grid method. Details of such a method are described in ISO 10289.
NOTE 2 The ISO ranking may be different from the ranking schemes used in other standards, e.g. the rusting evaluation ASTM D 610, where ranking is from 10 to 1, with 10 meaning no change and 1 meaning greatest change.
In addition to the ratings, the approximate dimensions of the area concerned shall be given, or the proportion of the area concerned compared with the total area, expressed as a percentage.ISO 4628-1 pdf download.
