Direkte Bestimmung von diffus-hemisphärischen Transmissions- und Reflexionsgraden von transparenten Wärmedämmungen, Fensterelementen und Abschattungsvorrichtungen

The optical properties of transparent insulation materials with complex structures can be characterised in many cases by the values for their transmittance and reflectance for ideal diffuse solar irradiation. A newly developed diffuse irradiation source allows quick and accurate measurements of the diffuse-hemispherical transmittance and reflectance of structured samples from 20 cm diameter up to 50 cm. Its newly developed inner coating, which consists of polytetrafluorethylene, assures the correct measurement of strongly selective angular and spectral properties of the samples.