ELSA, Procedure for calibration and verification of displacement and rotation measuring systems

The European Laboratory for Structural Assessment (ELSA) is a research facility of the DG JRC for the experimental assessment of structures, materials and components. Tests involve monitoring of the response of the specimens using a variety of sensors measuring forces, displacements, rotations, and deformations. Calibrating instruments prior to testing is crucial to generate reliable and accurate data. All the instruments to be installed on a specimen are calibrated prior to testing at ELSA ensuring the quality of measurements. The resolution, accuracy, reversibility, and repeatability of the signals from a measuring system are assessed through comparison with the output of reference sensors. Based on the calibration results, adjustments are made to the measuring system to correct possible errors and to conform to adopted standards. Finally, a calibration certificate is issued, documenting the calibration results and the performed adjustments. This document reports the calibration and verification internal procedures developed for displacement and rotation sensors, and adopted at ELSA as part of the quality assurance protocols. The procedures of the calibration of measuring systems are described, including information on i) the required ambient conditions, ii) the execution of the process, iii) the data treatment, iv) the calibration benches built at ELSA. The document includes an example of a calibration test report.