CORRECTED BALL DIAMETER CALCULATING METHOD AND FORM MEASURING INSTRUMENT

摘要

A corrected ball diameter calculating method includes: preparing a reference gauge that has at least one reference peripheral surface of an outer peripheral surface and an inner peripheral surface; valuing of diameter values of the reference peripheral surface at a plurality of different height positions from a bottom surface of the reference gauge; calculating calibrated diameter values per each of the height positions; placing the reference gauge on the rotary table and causing the stylus tip to touch a plurality of measurement sites on the reference peripheral surface at each of the height positions to calculate measured diameter values that are diameter values of a circle passing through the neighborhood of center points of the stylus tip; and calculating the corrected ball diameters per each of the height positions from the calibrated diameter values and the measured diameter values that are calculated per each of the height positions.