Development of a parameter to reflect the roughness of a wood surface that corresponds to tactile roughness - A novel filter to exclude local valleyeffects

The surface roughness of wood specimens was measured three-dimensionally and evaluated using a novel filtering method. This new filter excludes local deep valleys, such as vessels, from the mean line determined by ISO 4287. The roughness profile was estimated as the deviation of the primary profile from the modified mean line. Some peaks in the roughness profile, which are generated in and around vessels by conventional filters and are not due to the tactile roughness, were almost completely removed by this filter. The relative area of roughness-profile peaks above a certain threshold value corresponded to the tactile roughness. The conditions used for filters to exclude valleys are also discussed.