INSTRUMENT SCIENCE AND TECHNOLOGY Precision length measurement by computer-aided coordinate measurement

This paper gives a brief overview of computer-aided coordinate measurement as a method for testing the geometry of solid workpieces or components in mechanical engineering and similar fields. In contrast to conventional workpiece testing equipment, one can measure most kinds of workpiece with the coordinate measuring instrument as the only universal inspection centre. The principle is to measure a sample of surface points as space point coordinates, to evaluate them by means of mathematical models and computer software and to compute the desired sizes by using the computer’s internal digital model of the workpiece. A brief description of the various measuring instruments, the best-fit evaluation algorithms according to Gauss and Tsebyshev, the uncertainty and the software for the new workpiece inspection method oriented on flexible manufacturing systems are given.