Thermal insulation using solar control coatings reduces heating and cooling costs and adds color to architectural glass. To ensure all windows will match once installed, coaters must use the right solution to quantify color on non-scattering glass surfaces.
Controlling the color of coated glass panes holds many challenges:
The thickness of coating layers affects the color of the pane
Contaminated electrodes in the magnetron can cause stripes on the glass in the machine direction
All panes must match once installed; any color deviation will be easily noticed
Since glass is non-scattering, inline measurement devices with conventional geometries cannot provide accurate color data
Glass that looks correct on the line may exhibit defects once installed
A color measurement solution from X-Rite can take contactless measurements every second to evaluate color on coated glass panes. The system can include either the ERX54 or ERX56 non-contact spectrophotometer with a Xenon flash lamp to illuminate UV, visible range, and even INR up to 1000 nm with the ERX56. With a DE* of <0.3 on typical glass samples and repeatability of DE* <0.1 on the calibration mirror, both devices deliver the same readings as a sphere geometry measurement. The device can be mounted above the pane for low-E glass or below the pane for solar protection glass. Two ERX54 devices mounted on each side will measure transmission as well as reflectance from both sides.
ESWin software displays measurement results to characterize glass and coating color so operators can make clear pass/fail decisions, adjust color processes, and ensure glass is in tolerance before shipment. The reflectance data (1 nm optical resolution) can be shared with an external program to calculate adjustments on the coating layers. ESWin software also documents color quality records to verify the integrity of the program according to ISO 9001 and identify areas of improvement.
Monitoring color throughout production provides operators with real-time color information to avoid costly errors and rework.
The ERX54 and ERX56 can be mounted on a traversing beam for inline measurements above the line or on a stand for QC measurements in the lab. Both devices take non-contact measurements to capture accurate readings, regardless of thickness, without manually adjusting the measurement head.
For multi-silver layer measurements:
For ±15° reflectance and transmission measurements:
Measurement data is transferred to ESWin software to evaluate whether coatings are within tolerance and consistent before shipment.
Mounted inline or in the lab, this ±15° geometry instrument measures from a single reflectance angle to capture color. It offers a spectral range from 330 nm to 730 nm with 1 nm optical resolution for best-in-class measurement results. Real dual beam measurement delivers excellent short-term stability and automatic wavelength accuracy of <0.1 nm ensures exceptional measurement accuracy and long-term stability.
Mounted inline or in the lab, this multi-geometry instrument measures from three different angles (±15°, ±45°, ±60°) to replicate how color will shift when viewing angle changes. It offers a spectral range from 330 nm to 1000 nm with 1 nm optical resolution for best-in-class measurement results. Real dual beam measurement delivers excellent short-term stability and automatic wavelength accuracy of <0.1 nm ensures exceptional measurement accuracy and long-term stability.
Quality control software that works with ERX56 and ERX54 laboratory instruments to evaluate the color of functional layers on glass. It presents measurement results in an easy-to-interpret graphic display so operators can make clear pass/fail decisions in the lab and documents color quality records to verify the integrity of the program according to ISO 9001 and identify areas of improvement.
Custom Traversing Beam
A customized aluminum frame that can be built to fit any production line and mount the inline spectrophotometer above the web to measure multiple points in cross direction for continuous non-contact measurements from left to right.
Using the ERX54 or ERX56 spectrophotometer and ESWin quality control software, glass coaters can measure silver layer coatings, to ensure each pane is within color tolerance before shipment for a harmonious installation.