The main condition for the realization of a reinforced concrete construction is a complete coupling between the concrete and steel, used as reinforcement. Using higher quality steel, the force of the reinforcement has been increased and thus the risk of separation of these two materials. To avoid undesirable slip phenomena, great importance is put on the geometrical features of reinforcement steel used, i.e. the main contribution to the total adhesiveness lies in shear adhesiveness of the ribs or profiles on the surface of steel bars. Based on measured geometric features one can calculate a factor called the factor of adhesion or relative rib area. Therefore testing, i.e. concluding about the reliability of the measuring method with respect to the requirements of ISO 15630-1:2002, is the topic of this study. For that purpose measurements were preformed using two methods in order to calculate the factor of adhesion. First method was the optical method, using the instrument RM 302/202 manufactured by ECM Datensysteme GMBH. Furthermore measurements were preformed by the use of conventional length measurement equipment that is commonly available in production, sucs as dial indicators and vernier callipers. The obtained measurement results were subjected to statistical analysis as required by ISO 5725-1984 (E), and based on that the conclusions of the accuracy and reliability of measurement methods were made.