New Automatic Methods for Measuring and Quality Grading Pulpwood, 1998 Engineering Conference Proceedings

A new measurement technique and its associated frame image methods are discussed and the results reported from the first installation at Enso Ltd’s wood terminal at Kaukopää, Finland. The measurement system relies on laser and image processing technology. The solid volume of roundwood bundles are measured automatically on the basis of what is referred to as “frame volume“ and by measuring the visible logs on the surface of each bundle. The measurement station measures truckloads of roundwood to determine the volume, which facilitates the payment of wages and the purchase. The measurement time for one truck is approximately 30 seconds with total capacity of up to 120 loads per hour.

The mean deviation of the bundle-specific volume error for the equations formulated by timber assortment and degree of snow was approximately 4%. This bundle-specific accuracy satisfies the ±4% accuracy requirement of the measurement of a timber load, since even small loads of logs generally comprise of at least a few bundles. These results were previously reported in research report No 3/1996 by Metsäteho, Helsinki.

A modified design of this technology has also been supplied to Metsä-Rauma Ltd’s pulp mill in Rauma, Finland. As of July 1 st , 1997, the Finnish Agriculture and Forest Ministry have accepted this technology as an official measurement method.