This master's thesis compares two types of portable coordinate measuring machines; the laser tracker and the articulated arm. It includes a brief overview of the technology of laser trackers and articulated arms. The main part of the thesis is represented by the practical tasks and various scenarios that arise when using both measurement systems in the field. Based on these tasks, three instruments were compared: laser trackers Leica AT 403 and Leica AT 960 and the articulated arm Romer Absolute Arm 7525. Measurements were performed in the software Spatial Analyzer.