ISO 16474-2:2013 pdf free
ISO 16474-2:2013 pdf free.Paints and varnishes一Methods of exposure to laboratory light sources
The irradiance at any position in the area used for specimen exposure shall be at least 80 % of the maximum irradiance. Requirements for periodic repositioning of specimens when this requirement is not met are described in ISO 16474-1.
For some materials of high reflectivity, or/and high sensitivity to irradiance and temperature, periodic repositioning of specimens is recommended to ensure uniformity of exposures, even when the irradiance uniformity in the exposure area is within the limits so that repositioning is not required.
The design of the test chamber may vary, but it shall be constructed from inert material. In addition to the controlled irradiance, the test chamber shall provide for control of temperature. For exposures that require control of humidity, the test chamber shall include humidity-control facilities that meet the requirements of ISO 16474-1. When required by the exposure used, the apparatus shall also include facilities for the provision of water spray or the formation of condensate on the surface of the test specimens, or for the immersion of the specimens in water. Water used for water spray shall meet the requirements of ISO 16474-1.
The test chamber shall be equipped with a means of directing an intermittent water spray onto the fronts or backs of the test specimens under specified conditions. The spray shall be uniformly distributed over the specimens. The spray system shall be made from corrosion-resistant materials that do not contaminate the water employed.
The water sprayed onto the specimen surfaces shall have a conductivity below 5 μS/cm, contain less than 1 μg/g dissolved solids content and leave no observable stains or deposits on the specimens. Care shall be taken to keep silica levels below 0,2 ug/g. A combination of deionization and reverse osmosis may be used to produce water of the desired quality.ISO 16474-2 pdf download.
