Interaction of Opacity and On-Line Color Measurement, 1990 TAPPI Conference Proceedings
On-line color measurement of lightweight grades (opacity of 85% or less) is normally less than satisfactory. This is due to the fact that the on-line color measurement system is measuring a single thickness of the paper and the color as perceived by the on-line color measurement device is affected by small changes in opacity. To compensate for this undesired effect, an on-line opacity measurement device along with specialized software measures the opacity at various wavelengths in the visible spectrum and automatically compensates for the difference in calorimetric readings due to opacity variations. This paper discusses the techniques utilized in this procedure and presents data to illustrate the improvements in the correlation between the on-line and off-line color measurement readings that are afforded by this technique.
Interaction of Opacity and On-Line Color Measurement, 1990 TAPPI Conference Proceedings