Color Measurement For Coated Glass

Multiple silver layers on glass panes add functionality to architectural fronts. Low-E glass or solar protection is used all over the world to save costs for heating or cooling the house. Glass is a non-scattering product. So far in the laboratory a d:8° instrument with specular component included has been used to measure glass panes. Because of the non-scattering surface of the glass pane, just the small illumination which came from the gloss angle at -8° is a useful illumination for the measurement; all the other directions of illumination are not effective. X-Rite developed a measurement geometry where the pane is illuminated with a specific angle and the measurement will be taken right on the other side, directly in specular. This ensures a non-contact measurement with a high distance variation to measure different thicknesses of panes without mechanical adjustments.

X-Rite has two different geometries available:

Version ERX54 The glass will be illuminated under 15° and measured with -15°. This measurement gives the same readings like in the laboratory with a sphere geometry measurement (d:8°, SPCI). If two instruments are combined, not only the reflectance can be measured from both sides of the pane, but also transmission.

Version ERX56: This instrument has three geometries +15°:-15°, +45°:-45° and +60°:-60°. The 15° measurement gives the same readings as in the laboratory with a sphere geometry measurement (d:8°, SPCI). To see the color change in different observer angles the 45° and the 60° measurement gives useful information.