Uncertainty Determination for Dimensional Measurements with Computed Tomography

Due to the availability of increased computational power combined with better X-ray source and detector technologies, the obtainable resolutions now allow to use CT-machines not only for material and medical science, but also for dimensional metrology. However, the transition from visualization to measuring requires calibration steps to ensure that measurements are traceable to the unit of length. There is still a lack of proper standards to calibrate CT machines and to check their performance for dimensional metrology. In addition, there is still room for a better systematic approach for measurement uncertainty determination. Therefore, this paper presents a method to determine the uncertainty of dimensional measurements with industrial CT machines based on the ISO-GUM. Subsequently, some of the uncertainty factors are quantified based on a series of systematic measurements.