This part of GB/T 16422 specifies test methods for exposing plastic specimens to xenon-arc source in the presence of moisture to reproduce the weather aging effects that occur when materials are exposed in actual end-use environments to daylight or to daylight filtered through window glass.
The specimens are exposed to filtered xenon-arc light source under controlled conditions (temperature, humidity and/or wetting). Various types of xenon-arc light sources and various filter combinations may be used to meet different requirements.
Specimen preparation and evaluation of the results are covered in other international standards for specific materials.
General guidance is given in GB/T 16422.1.
Note: Xenon-arc exposures of paints and varnishes are described in ISO 11341.
2 Normative references
The following referenced documents are indispensable for the application 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 4582 Plastics - Determination of changes in color and variations in properties after exposure to daylight under glass, natural weathering or laboratory light sources
ISO 4892-1 Plastics - Methods of exposure to laboratory light sources - Part 1: General guidance
3 Principle
3.1 A xenon arc, fitted with suitable filters and properly maintained, is used to simulate the spectral power distribution of daylight in the ultraviolet (UV) and visible regions of the spectrum.
3.2 Specimens are exposed to various levels of light, heat, relative humidity and water (see 3.4) under controlled environmental conditions.
3.3 The exposure conditions may be varied by selection of:
a) the light filter(s);
b) the irradiance level;
c) the temperature during exposure to light;
d) the relative humidity in the chamber during light and dark exposures, when humidity of exposure conditions is required to be controlled;
e) the way the test specimens are wetted (see 3.4);
