IEC 60068-2-5 pdf download Environmental testing – Part 2-5: Tests – Test Sa: Simulated solar radiation at ground level and guidance for solar radiation testing
5.3 Humidity Different humidity conditions, particularly condensation, can markedly affect photochemical degradation of materials, paints, plastics, etc. If required, the values of IEC 60068-2-78 shall be preferred.
The relevant specification shall state the humidity and whether it is to be maintained during
a) the irradiation periods only;
b) the periods of darkness only;
c) the whole test duration.
5.4 Ozone and other contaminating gases Ozone, generated by short wavelength ultra-violet of test sources, will normally be excluded from the test chamber by the radiation filter(s) used to correct the spectral energy distribution. As ozone and other contaminating gases can significantly affect the degradation processes of certain materials, it is important to exclude these gases from the test chamber, unless otherwise required by the relevant specification.
5.5 Surface contamination Dust and other surface contamination may significantly change the absorption characteristics of irradiated surfaces. Unless otherwise required, specimens should be tested in a clean condition. However, if effects of surface contamination are to be assessed, the relevant specification should include the necessary information on preparation of surfaces, etc.
5.6 Mounting of specimen The specimen to be tested shall be placed either on raised support, on a turntable or a specified substrate of known thermal conductivity and thermal capacity within the chamber as stated in the relevant specification, and so spaced from other specimens as to avoid shielding from the source of radiation or re-radiated heat. Temperature sensors should be attached to specimen as required.
5.7 Test facility It shall be ensured that the optical parts of the test facility, lamps, reflectors and filters, etc. are clean. The level of irradiation over the specified measurement plane shall be measured immediately prior to each test. Any ancillary environmental conditions, e.g. ambient temperature, humidity and other parameters if specified, should be monitored continuously throughout the test.
5.8 Test apparatus The chamber in which the tests are to be carried out shall be provided with means for obtaining, over the prescribed irradiation measurement plane, an irradiance of 1 1 20 W/m 2 ± 10 % with the spectral distribution given in Table 1 . The value of 1 120 W/m 2 shall include any radiation reflected from the test chamber and received by the specimen under test. It should not include long-wave infra-red radiation emitted by the test chamber.
Means shall also be provided whereby the specified conditions of temperature, air flow and humidity can be maintained within the chamber.