DIN 53231:1991-04

1 Scope and field of application
2 Concepts
      2.1 Ageing criterion
      2.2 Radiant exposure
      2.3 Ageing behaviour on exposure to artificial
             weathering and exposure to radiation in
             laboratory apparatus
3 Principle
4 Apparatus
      4.1 Test chamber
             4.1.1 Artificial light source and filter
                      system
             4.1.2 Conditioning of test chamber
             4.1.3 Device for wetting test panels
                      (method 1)
             4.1.4 Device for producing condensation on
                      test panels (method 1)
             4.1.5 Test panel holders
      4.2 Black standard thermometer
      4.3 Radiometer
5 Sampling
6 Test panels
      6.1 Preparation
      6.2 Number
7 Procedure
      7.1 Mounting test panels
      7.2 Black standard temperature
      7.3 Exposure of test panels
      7.4 Wetting of test panels and control of relative
             humidity in test chamber
      7.5 Exposure of test panels together with control
             specimens
      7.6 Exposure time
8 Evaluation
9 Expression of results
10 Test report
Annex A - Irradiance values for global radiation and exposure
          to artificial radiation
Standards and other documents referred to
Explanatory notes

Paints, varnishes and related products (referred to below as 'coatings', for short) are exposed to artificial weathering and radiation in laboratory apparatus when the aim is to simulate or quantify the ageing processes due to exposure in the open air or, by means of a suitable test arrangement, behind glass. As compared with natural weathering, artificial exposure in the laboratory involves a smaller number of parameters, but these can be more readily kept constant and their influence so adjusted as to yield conditions which permit testing to be accelerated.