Calibration of coordinate measuring machines

For over three years the Physikalisch-Technische Bundesanstalt has been investigating the numerical error correction of cmms, and the relationships between problems in this area and in the calibration of these machines. It has been determined that calibration is possible, for pre-defined conditions, but that the calibration is applicable only to the particular measuring task and conditions. This paper describes the mathematical model used by PTB and gives results of tests on a cmm.