Accuracy of grooves or ridges measurement methods and precision measuring device and accuracy of evaluation Allowed way

摘要

PURPOSE:To enable measurement of precision of a groove or a projecting thread in the height and width directions by a one-dimensional displacement measurer by a method wherein displacement in the height direction at one point on each of a pair of slanting surfaces constituting the groove or the projecting thread is measured along the longitudinal direction thereof and each factor in a series of measured data thereon is processed by a specific method. CONSTITUTION:Detection signals of an electric micrometer 35 and displacement sensors 41 and 42 detecting displacements of reference surfaces 40a and 40b are supplied to a controller 45. Executing a subsequent processing, the controller 45 measures the precision of a thread groove of a nut 40, for instance, and outputs 46 the result thereof. Concretely, first the displacement in the height direction at one point one each of a pair of slanting surfaces constituting the groove is measured along the longitudinal direction of the groove. Next, each factor in a series of measured data thus obtained is put in a group of corresponding factors between the series of measured data. Based on the sum of the grouped factors, in succession, the precision of the groove in the height direction in regard to a groove used as a reference is determined. Based on a difference between the grouped factors, besides, the precision in the width direction in regard to the groove used as the reference is determined.