Arrangement for vertical angle calibration of geodetic instruments

Many opto-electronic digital instruments, such as rotary encoders, theodolites, total stations, laser trackers, etc. are used in machine engineering and instrumentation, geodesy, surveying, robotics and other branches of industry. Most of optical - electronic geodetic measuring instruments consist, among the other elements, of the circular scales and angular transducers for angle determination in two perpendicular planes - horizontal and vertical. Accuracy of the instrument mostly depends on the accuracy of these means for angle measurement. Metrology of the angular transducers including the raster scales has some specific features and needs the specific arrangements for its calibration. Here we present a review and some simple means and methods that can be used in the angle measurement metrology, especially for vertical plane angle calibration.