Three European laboratories performed transmittance and reflectance measurements on the same coated glass samples and used different methods for the determination of the complex refractive index and thickness of the coatings. The optical constants of the glass substrates (taken from the literature or obtained by preliminary characterisation of the uncoated glass sheets) and coatings were used to simulate the daylighting behaviour of the coated glass sheets in real conditions as fenestration of a room. In spite of the discrepancies in the optical constants obtained by the laboratories for each coating (mainly due to different hypothesis on the coating structure and homogeneity) the corresponding coated glass gave similar results for the luminous transmittance and reflectance obtained by integration of the computed data and for the illuminance inside the room obtained by applying a suitable computing program. Therefore, for the considered application it is not necessary to know either the exact composition of the coating or its optical constants: an equivalent homogeneous film which reasonably well reproduces the experimental luminous parameters of the coated glass at the different angles of incidence can be used.
|Pages (from-to)||202 - 209|
|Number of pages||8|
|Publication status||Published - Dec 1997|
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
Montecchi, M., Van Nijnatten, P. A., Polato, P., & Roos, A. (1997). Spectrophotometric characterisation of coated architectural glass sheets and its role in the simulation of daylight behaviour of glazing. Glass Technology, 38(6), 202 - 209.