ETA's Windows Group has a complete set of instruments designed to characterize the detailed radiometric and optical properties of solar energy materials, and in particular, glazing and shading materials for windows. These include a photo-goniometer to measure light transmission and reflection of light-emitting, light-scattering and light-redirecting materials, and a spectro goniometer to measure angle-resolved scattering versus wavelength.

• Optical spectrocscopy (300–2,500 nanometers [nm])
• Variable-angle spectral ellipsometry (300–1,700 nm)
• In-plane angle-resolved scattering (300–2,500 nm)
• Thermal emissivity