The performance factors and spectral details of the coated glass shall be determined using standard accepted spectrophotometer equipment. The exact size will be determined by the type of measuring equipment employed. The transmittance of the measuring sample must be measured using normal incidence light at the following wavelengths: 1. 550 µm (representative wavelength for light and solar transmittance) 2. 900 µm (representative wavelength for solar transmittance) 3. R- reflectance measurement shall be made at 8 µm using radiation of nearly normal incidence for glass said to have a low emissivity coating.