Measurement of cylindrical form errors using a non-contact detector

Abstract Measurement using a spherical tip stylus cannot give a correct assessment of cylindrical form errors of finely turned parts due to their cutting tool marks. The electrostatic-capacitance type gap sensor applied in this research is useful in eliminating the influence of cutting tool marks, which should be regarded as the surface roughness. The sensor does not damage the cylinder surface, as a stylus might. Further, two measuring methods, a round tracing method and a spiral one, were compared