Abstract
There is a strong demand to insure traceability for the quality of gears. We propose a novel multiball artifact (MBA) for evaluation of pitch measuring accuracy of gear measuring instruments (GMIs). The aim of the MBA is to transfer minimum uncertainty from a calibrated value at a national institute to GMIs of a shop floor. The MBA is composed of equally spaced balls around an axis. The balls can be manufactured with profile accuracy of several tens of nanometers. Commercial GMIs can measure the pitch deviation of the MBA without special software because the virtual gear dimension for the MBA is built. We calibrated the MBA at the National Metrology Institute of Japan (NMIJ) and we evaluated the pitch measuring accuracy of a GMI using the calibrated MBA. The MBA was useful calibration artifact that can be transferred the small uncertainty from the NMIJ to the GMI.
