We determine Visible light, solar properties and thermal radiation properties of a double glazing unit determined according to EN, ISO and NFRC standards.
The basic optical properties for the calculation of solar energy transmittance and daylight properties of glazing are the reflectance and transmittance spectra of the individual panes at normal incidence. The standard procedure is to measure the transmittance and reflectance of small samples at (near-)normal incidence using a spectrophotometer in the wavelength range 280 nm – 2,500 nm.
For determining the thermal radiation properties we use an IR Spectrophotometer equipped with a 10° regular reflectance accessory to measure the spectral reflectance at (near-) normal incidence in the wavelength range 2,500 nm – 50,000 nm
The results are summarised in a test report: