Calibration of the levelling rods using laser interferometer

Abstract

In this paper, a method of calibration of the levelling rod Carl Zeiss Jena No. 55822 was proposed. Within a method procedures we follow the requirement of the International Standard ISO/IEC 17025: 2005 and all necessary observations were performed in the Metrological Laboratory of Institute of Geodesy and Geoinformatics, Faculty of Civil Engineering, University of Belgrade. In the process of the calibration, we used a laser interferometer Hewlett Packard HP 5528 and specially adapted auxiliary equipment for placing the levelling rod in appropriate horizontal position. In addition to the testing of the quality of the graduation of the levelling rod several other properties were examined in order to adequately check the error budget of its application in future Besides of all mentioned, paper also provides an adequate mathematical model of measurement, including the standard estimations of input observation values as well as a measurement uncertainty. The described calibration procedure can be applied to any linear measurement devices.