1 Scope
This standard specifies exposure conditions for paint coatings exposed to artificial weathering in apparatus including fluorescent UV lamps and condensation or water spray. The effects of weathering are evaluated separately by comparative testing of chosen parameters.
NOTE The ultraviolet light produced by fluorescent lamps simulates only part of the UV region of natural sunlight and, consequently, the test pieces are subjected to a small but destructive portion of the spectrum.
Due to the lack of visible and infra-red energy in the light from such UV lamps compared to sunlight, the test pieces are not heated above the temperature of the surrounding air in the way in which they would be in practical use.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated reference, subsequent amendments to (excluding any corrigendum), 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 editions of the standards indicated below. For any undated references, the latest edition of the document referred to applies.
GB/T 3186 Paints, varnishes and raw materials for paints and varnishes — Sampling (GB/T 3186-2006, ISO 15528:2000,IDT)
GB/T 6682 Water for analytical laboratory use - Specification and test methods (GB/T 6682-2008,ISO 3696:1987, MOD)
GB/T 9271 Paints and varnishes — Standard panels for testing (GB/T 9271-2008, ISO 1514: 2004,MOD)
GB/T 13452.2 Paints and varnishes — Determination of film thickness (GB/T 13452.2-2008, ISO 2808: 007, IDT)
GB/T 16422.1-2006 Plastics - Methods of the exposure to laboratory light sources - Part 1: General guidance (ISO 4892-1: 1999, IDT)
GB/T 20777 Paints and varnishes — Examination and preparation of samples for testing (GB/T 20777-2006, ISO 1513: 1992,IDT)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
ageing criterion
given degree of change in a selected property of the coating under test
