In laboratory accelerated weathering instruments, different light sources are combined with optical filter systems to meet spectral requirements, which are specified in testing standards. These requirements usually refer to solar radiation reference spectra, which are published in internationally agreed documents.
For realistic and precise (i.e. reproducible and repeatable) testing, simulation of the solar spectral power distribution and amplitude (irradiance) is critical. This is most important for solar radiation capable of initiating photochemical reactions, the so-called “actinic” wavelength range.
This 21-page Technical Guide provides a comprehensive overview about