This book presents the main methods and techniques for measuring and monitoring the accuracy of geometrical parameters of precision Computer Numerically Controlled (CNC) and automated machines, including modern coordinate measuring machines (CMMs). Highlights include: • Standard methods and means of testing, together with methods newly developed and tested by the authors; • Various parameters, such as straightness, perpendicularity, flatness, pitch, yaw, and roll, as well as the principal processes for measurement of these parameters; • Lists and tables of geometrical accuracy parameters, together with diagrams of arrangements for their control and evaluation of measurement results; • Special methods and some original new devices for measurement and monitoring, information measuring systems (consisting of laser interferometers, photoelectric raster encoders or scales, etc.), and methods for the measurement and testing of circular scales, length scales, and encoders; • Methods for measuring small lengths, gaps, and distances between two surfaces; • Examples showing the suitability of mechatronic methods for high accuracy correction of machines; and • Particular attention is given to the analysis of ISO written standards of accuracy control, terms and definitions, and methods for evaluation of the measurement results during performance verification.