The vertical comparator which was built in the Geodetic Metrology Laboratory of the Faculty of Mining Surveying and Environmental Engineering of the AGH University of Science and Technology in Krakow is used to determine the precise calibration corrections of invar, fiberglass and technical rods, depending on user requests. The paper presents the results of the calibration of selected types of barcode rods known as engineering levelling rods – folding, uniform rods made of fiberglass designed for Leica and Topcon levelling instruments and folding rods made of wood for Trimble DiNi levelling instruments. Based on the results of calibration, an analysis of graduation errors was performed for different types of rods. For folding rods, large errors in graduation of up to 0.3 mm were found upon contact with elements. Errors were found to be cumulative when readings back and forth were performed on different segments of the rods or when there was a large difference in the height between points. The coefficients of scale for various sections of the rods varied considerably. The paper assesses the suitability of engineering rods for measuring a detailed levelling network, including measuring the configuration of the terrain on which the levelling is performed.

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