Simulation-based sensitivity analysis of geometrical misalignments in X-ray computed tomography systems for dimensional metrology – detector angular misalignments

Abstract

Nowadays, X-ray computed tomography (XCT) represents a viable solution for metrological investigations of industrial components characterized by external as well as internal geometries. However, the traceability of measurements is still difficult to be established because of a great number of influence factors, often difficult to be identified and assessed. The XCT system geometry represents one of the most critical aspects, as any deviation from the ideal alignment conditions may generate errors in measurement results. Many efforts have been made to find methods able to characterise the actual geometry of the system, but work is still needed to obtain faster and easier solutions. This work is part of a study that aims at investigating the magnitude of dimensional measurement errors caused by geometrical misalignments that can affect an XCT system, with the purpose of developing a faster and easier solution by focusing on the most critical factors. Results of a simulation-based investigation on the influence of detector angular misalignments are presented. The center-to-center distances of spheres belonging to a newly designed ball plate are evaluated, starting from angular misalignments already investigated experimentally in literature.