Coordinate Measuring Machines (CMMs) are now the principle measuring instrument used for quality control of the dimensions of manufactured parts. In order to ensure that the accuracy of these machines is sufficient for the intended use, performance standards are required. The author will write a new updated version of the American National Standard for the performance of CMMs in close cooperation with the American Society of Mechanical Engineers (ASME) B89.1.12 committee who approves this standard. The new standard will remove ambiguities identified in the previous version (1985), improve the section on ball bar measurement, and add treatments for rotary axes, large machines and "touch-fire" probes. A completed version of this standard will be delivered to the committee in September of 1989.
