Inter-laboratory comparison using integrating sphere spectrophotometers to measure reflectance and transmittance ofspecular, diffuse, and light-redirecting glazing products

摘要

An inter-laboratory comparison (ILC) between glazing manufacturers that submit data to the International Glazing Database (IGDB) is carried out every four years. This time a large number of independent laboratories were included in addition to the IGBD submitters, in total over 50 boxes of samples were sent out in parallel. Each box contained 5 specular samples, consisting of clear float glass, low-e coated glass, laminates, and an applied film on clear glass. New for the IGDB submitters were 5 diffuse samples, 2 fritted glass samples, a diffuse laminate, a light-redirecting daylighting film, and a shade fabric with an inhomogeneous pattern. The samples were characterized by each participant in the solar optical range, 300 nm - 2500 nm, as well as the thermal infrared from 5iµm/i–25iµm/i. Spectral data was inspected for anomalies such as systematic absorption and non-continuous steps due to instrument design and operation. Spectral averaged data was calculated and used to compare the results from the different laboratories. Such comparisons indicated that use of a diffuse reference for specular measurements marginally increased the measured result. For diffuse products the effects of sphere geometry and design influenced the results to a significant degree.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.