Error related factors in CT dimensional metrology

Since its invention in the early 1970´s, computed tomography (CT) has played a vital role for both medical and material inspection applications. More recently, CT has entered the domain of dimensional metrology, facilitating the measurement of interior structures. This paper concentrates on the assessment of CT measurement accuracy by investigating a series of influencing factors, such as the size of work pieces as well as the influence of surrounding material. In addition, the paper discusses grey value profiles of experiments that were designed to investigate the possibility to create a calibration database as a strategy to improve the measurement accuracy. Finally, the paper describes the influence of the reconstruction software settings on the CT accuracy.