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.

Coordinate measuring machines (CMM) are traditionally used in industry for verifying geometric dimensions and tolerances of parts. In the last decade X-ray computed tomography (CT) is being increasingly used in industry for dimensional analysis purposes as well. Tactile CMM is based on point-to-point collection of measurement data, while CT scans entire workpiece and generates a volumetric point cloud of measurement data. The influence of different approaches in gathering of data when using CMM and CT on calculation of voxel size is experimentally tested and discussed in this work and compared with other standard voxel size calibration options like use of reference standards and calibration of magnification axis. Several typical industrial workpieces are used to demonstrate the differences that arise because of different voxel size calibration strategies.

Prohibitive cost of available commercial gauge block interferometers resulted in numerous retrofitting projects in National Measurement Institutes, upgrading old gauge block interferometers to be used with laser sources and digital interferogram acquisition and processing. We demonstrate the possibility of building a new gauge block interferometer using mostly off-the-shelf components, with comparatively low cost and sufficiently high accuracy. Additional advantages over retrofitting are that an open platform for further research is obtained, and that reconfiguration to accommodate various measurement objects other than gauge blocks is possible. In this paper we will present the design of new phase shifting gauge block interferometer built at Croatian National Laboratory for Length, preliminary measurement results, and compare it with a retrofitted Zeiss gauge block interferometer.

The major problem related to ensuring measurement unity in the field of dimensional nanometrology can be addressed to lack of norms that defines characteristics of measurement standards for that field of metrology. In Laboratory for precise measurements of length (LFSB) significant efforts have been made in order to investigate metrological characteristics of standards in the field of microand nanometrology. In this paper we present results of intensive work and research carried out in LFSB in order to develop standard in the field of dimensional nanometrology that will significantly contribute to the insurance of measurement unity in that field of metrology.

Traceability of physical length to the SI unit of meter is realized by means of interferometry, and primary interferometers are used at the highest accuracy levels to perform calibration of national gauge block standards. These devices are very expensive, given the fact that they are manufactured on order and used almost exclusively by national measurement institutes. Therefore, LFSB decided to retrofit and modify an existing Zeiss gauge block interferometer, and preliminary measurements show substantial improvements in accuracy.