Measuring the "Color" of Glass Plates

Color measurement is important to many industries with applications in food, textiles, pharmaceuticals, and glass works, to name a few. All humans see color differently, and in many cases, color perception can vary between eyes of the same individual. Furthermore, the color of an object perceived is also dependent upon the spectral irradiance of the illuminant used to view the object. Because of these differences, the ability to quantify a given color value becomes very important.

One way of achieving this quantitation is by the use of color space analysis. In color space, a spectral scan of a given color is integrated with both standard observer responses for red, green, and blue and with standard responses for various illuminants. The final result provides a set of distinct values that represents the color of the object.

To demonstrate the measurement of color on two different Shimadzu UV-Vis spectrophotometers, spectra were acquired of a set of glass filters. Scans were acquired with a Shimadzu UV-1800 spectrophotometer and a Shimadzu UV-2600 spectrophotometer equipped with and without an ISR-2600Plus Integrating sphere. The spectral scans were acquired as transmission scans between 400 and 800 nm and analyzed using the Shimadzu Color Analysis Software. The CIELAB color space was selected for comparison using a D65 selection (Midday light) as illuminant.