A method and apparatus are provided by which a sheet-forming web may be characterized in four dimensions. Light images of the web are recorded at a point adjacent the initial stage of the web, for example, near the headbox in a paperforming operation. The images are digitized, and the resulting data is processed by novel algorithms to provide a four-dimensional measurement of the web. The measurements include two-dimensional spatial information, the intensity profile of the web, and the depth profile of the web. These measurements can be used to characterize the web, predict its properties and monitor production events, and to analyze and quantify headbox flow dynamics.
STATEMENT OF GOVERNMENT RIGHTS
This invention was made with United States Government support under Contract Number DE-AC05-96OR22464 awarded by the United States Department of Energy to Lockheed Martin Energy Research Corporation and the United States Government has certain rights in this invention.