COORDINATE MEASURING METHOD AND APPARATUS FOR INSPECTING WORKPIECES, COMPRISING GENERATING MEASUREMENT CORRECTION VALUES USING A REFERENCE SHAPE THAT IS KNOWN NOT TO DEVIATE SUBSTANTIALLY FROM A PERFECT FORM

摘要

A series of nominally identical production workpieces are measured (88) on a workshop coordinate measuring apparatus. They are corrected (90) using correction values generated (84,86) by comparing coordinate values of a reference workpiece measured (82) on the workshop apparatus with corresponding values derived from external measurements (70,74). To reduce the care and skill required, the external measurements are used to determine reference values (76) of a geometric property of a feature of the reference workpiece, rather than coordinate values corresponding directly to those made on the workshop apparatus. Corresponding coordinate values are then generated (80) from knowledge of the perfect form (72, 78) of the feature of the reference workpiece.