| 摘要 |
In an illustrated embodiment, brightness, color, opacity and fluorescent contribution to brightness are measured by an on-line sensing head providing for simultaneous measurement of transmitted and reflected light. By measuring two independent optical parameters, paper optical properties of a partially translucent web are accurately characterized substantially independently of paper grade and weight. The instrument id designed so as to be capable of transverse scanning of a moving paper web on the paper machine, and so as to monitor desired paper optical characteristics with sufficient accuracy to enable on line control of the optical characteristics of the paper being manufactured. |
