Investigation on scan parameters for accurate dimensional measurements by CT helical scanning

In industrial X-ray computed tomography (CT), conventional scans using circular trajectories face limits when dealing with internal and complex features on elongated workpieces, mainly due to the dimensions of the detector. To this extent, helical scanning is a powerful solution that enhances flexibility of the system and, when using suitable parameters, enables obtaining a strong improvement on image quality, eliminating the cone-beam artifacts that characterize conventional scans. In this work, metrological performances in CT helical scanning are experimentally investigated and compared with those of conventional circular scans. The influence of main helical scan parameters are studied to enhance accuracy of dimensional measurements by CT helical scanning.