Interlaboratory comparison of ultraviolet transmittance and reflectance of coated and uncoated flat glass : Report of the International Commission on Glass Technical Committee 10 "Optical Properties of Glass"

Abstract

Glass manufacturers generally characterize the ultraviolet behaviour of flat glass (glass for building or automotive applications) by normal incidence spectrophotometry. Intercomparisons have been organized by Technical Committee 10 of the International Commission on Glass among its members and one metrological Institute on spectrophotometric evaluations of ultraviolet transmittance and reflectance on uncoated and coated glasses. Spectral transmittance and reflectance were measured in the 280 to 380 nm ränge and parameters like UV transmittance and UV reflectance were computed following a procedure recommended by a European Standard. The purpose of these round robins was to assess the interlaboratory reproducibility and accuracy of the spectral measurements and of the computed values obtained by integration of the experimental data in the ultraviolet ränge. UV transmittance and UV reflectance were then evaluated for the selected samples using two new different ultraviolet radiation tables proposed by the International Organization for Standardization to evaluate the difference in the results obtained by applying the different Standard procedures. Finally, measurements were also performed in the first part of the visible ränge and a "Krochmann Damage Factor" was evaluated for the considered samples.