Performance monitoring of geodetic instruments

The paper deals with the performance monitoring of angle measuring instruments used in geodesy and machine engineering. Together with an instrument's performance monitoring, accuracy monitoring provides the most important information about both features. In fact, speaking of an instrument's performance is meaningless unless its accuracy is taken into account. The instrument is calibrated against the reference standards of measure comparing its accuracy at some intervals of calibration. It depends on published standards and technical specifications for these instruments. Geodetic instruments - rotary tables of metal cutting tools and instruments, linear and rotary encoders - produce a great number of discrete values. The theoretical and technical background for monitoring the accuracy of performance of angular measurement instruments used in geodesy and machine engineering are described. A test-rig for monitoring angular accuracy is described. The main concepts of circular scales measurement has been chosen as the basis for developing a monitoring system. Since circular scales are employed in almost all measurement systems and rotary encoders, they play an important role in monitoring their accuracy parameters. The new scale calibration method discussed is applied for extensive and informative monitoring and assessment of performance and accuracy of geodetic instruments.