Assuring the Day-to-Day Accuracy of Coordinate Measuring Machines—A Comparison of Tools and Procedures

The continual use of coordinate measuring machines (CMMs) in high-volume manufacturing has led to several applied standards. With the ever-increasing emphasis on quality, annual certification of conformity by a qualified outside calibration service is no longer adequate. An artifact can be used in an interim testing plan to evaluate machine performance between certifications. The objective of this paper is to evaluate the design of artifacts, evaluate the analytical procedure to estimate certain characteristics of CMM performance, and evaluate the artifacts’ repeatability and accuracy measurements. The capability of two traceable artifacts (one 2-D and one 3-D design) and a machine checking gage were assessed. The results indicate that an artifact can be used for interim performance evaluation but not for calibration or certification.