As the power and accuracy of coordinate measuring machines (CMMs) increase, their role in the calibration of artifacts and precision parts becomes more wide spread and economical. This is particularly true when the artifact geometry is complex and intricate. The role of CMMs in calibration activities at NIST and a description of their use measuring threaded plug and ring gages for the American Petroleum Institute (API) is presented. Aspects of CMM performance characteristics, such as those specified in the ANSI/ASME B89.1.12 standard will also be described. The use of "accuracy enhancement" techniques, also known as "software error compensation", will be illustrated by testing their effectiveness on CMM accuracy.
展开▼
