Precision inspection of diameters for circular reflecting cylinders

摘要

The urgent problem for industrial inspection is non-contact precision measurement the diameters of circular reflecting cylinders, namely, rolling bearing elements with diameter from 10 mm to 50 mm must be inspected with error no more than 1 μm. Diffraction method for measurement of diameters of circular reflecting cylinders is presented. Peculiarity of this method is rather measurement gaps between two cylinder vertexes and two reference half-planes, than measurement of cylinder diameter by direct Fraunhofer method. Equivalent model of formation of Fraunhofer diffraction pattern by measurable object is developed. Using this model an algorithm of diffraction pattern processing was suggested that allows determining gap between object edges and reference half-planes with error no more than 1μm.