Abstract
Our previous study showed that the values of surface roughness for direction-dependent grooves on the standard surface roughness plates were dependent on the measuring angle (MA). Thus, the parameter of surface roughness might differ appreciably for different MA values. This study was to evaluate the effects of directional dependence of surface roughness on standard surface roughness plates with direction-dependent grooves. The optimal MA for direction-dependent surface roughness was determined by equivalent equation of a wave length parameter (Rλa). The optimal angle range of MA was determined by the Rλa-tolerance (Rλa-TOL) method in terms of 10% TOL value of equivalent equation of Rλa. This Rλa-TOL method was effective for measuring direction-dependent surface roughness, such as that of the standard surface roughness plate.
