Translucent glass components used in a fenestration allow a more uniform illuminance distribution in interiors and avoid direct sunlight near the window which can cause discomfort. No standardized procedure is available for the daylighting characterization of diffusing fenestration. Moreover, commercial integrating sphere spectrophotometers usually used to evaluate the optical parameters of glass cannot be utilized for glazing systems. More precisely, the glazing systems cannot be positioned in the sample compartments of the instruments while in the case of translucent glass components, the results obtained by different spectrophotometers depend on geometric conditions of irradiation and observation of the samples and therefore, cannot be compared. A prenormative work is therefore required to establish the most convenient instruments and procedures.
