Measurement of mean coarseness of workpiece surface - using length gauge generating voltages corresponding to surface peaks and valleys

摘要

The measurement of mean coarseness of a workpiece surface is made by scanning using an electrical length gauge passed over the tested workpiece surface divided in e.g five measurement sections. It generates voltages corresponding to the surface peaks and valleys. Difference between highest peak and lowest valley in each section is formed by a summating device, and a device forming mean values is provided. Difference voltages corresponding to the coarseness of the n sections are consecutively added to the previously obtained sum, and the mean roughness of the surface is determined by dividing the sum total by n.