Design of a calibration machine for linear scales

The aim of the project described in the paper was - based on the experiences with the previously designed fully automatic scale measuring machine - to develop a cheaper version for small calibration laboratories. In this case we were not restricted by the special constraints of the customer. In new version the conventional guideways were replaced by vacuum preloaded flat air bearings and the motion system by manually operated friction drive. Using the same optic an improved picture processing and evaluation algorithm was implemented. The paper includes the uncertainty budget and some results gained with the machine.