Available spectrophotometers allow the measurement of the spectral transmittance (T) and reflectance (R) of optical components only at normal incidence. From these data it is possible to obtain a rough estimate of the daylight and solar parameters of the glazing materials used for building and car windscreens. However the realistic computation of natural lighting inside structures requires the measurements of T and R at different angles of incidence, to account for the fact that the angle of the sun is a function of hour, data and latitude.
As a prerequisite to the development of an improved method for determining the angular dependence of T and R, this project will be carried out along two parallel activities:
a) an intercomparison of the features of the existing instruments modified to perform such measurements on a limited scale,
b) a preliminary feasibility study to demonstrate that a new proposed technique is capable of meeting the prescribed requirements.
The work is in progress.
Funding SchemeCSC - Cost-sharing contracts