Summary:

The need for periodic testing of surveying equipment is often treated by surveyors as a "necessary evil". Research conducted in the Metrological Geodetic Laboratory GLM AGH shows that the periodic calibration of surveying instru-ments allows to detect and describe the systematic errors, and generate proposals for the proper use of equipment, which leads to maintaining the accuracy required under the legislation.
The article presents conclusions from laboratory tests of leveling rods, which can help to improve the accuracy of precise leveling. These considerations are particularly important for measurements carried out in the mountains and in engineering measurements of the highest accuracy.