Remote On-Line Color Measurement for Finishing Operations

On-line color measurement and control systems are employed in a number of manufacturing operations to monitor continuously the color of products moving through the production process. They enable operators to identify color variations before they exceed tolerances and to adjust formulas or metering rates without disrupting operations. They have proved most successful in measuring products displaying solid colors or relatively smooth surfaces. An advanced system designed to inspect large shapes and make more consistent measurements of finishes on curved surfaces is described. It utilizes a pulsed-xenon sensing unit that can be positioned anywhere from four to twenty feet from the surface to be measured and provide an accuracy comparable to that of an industrial spectrophotometer. This remote arrangement for the sensor provides a larger area of view, a greater depth of focus and a greater distance from the production line. The significance of these features is discussed.