Voxel size and calibration for CT measurements with a small field of view

Abstract

Dimensional tomographic measurement is influenced by many factors. To achieve metrological traceability of results, knowledge of influence factors and their effect on measurement is important. This includes knowledge of the true value of voxel size and edge detection. Phantoms used for characterization and correction of error sources are calibrated usually on tactile or optical coordinate measuring machines. The challenge here is the manufacturing and calibration of small phantoms, which can be used in the field of view approximately 1 mm and less, which is the case of tomographic devices aiming at high resolution. In this work, abilities of a nano-coordinate measuring machine (nano-CMM) SIOS NMM-1 (Nanopositioning and Nanomeasuring Machine) to calibration of a phantom for X-ray computed tomography (CT) with the small field of view and high resolution are tested.