While computed tomography (CT) has long been used for medical applications and material
inspection, its application field has recently been broadened to include industrial dimensional
metrology. However, the accuracy of CT-based measurements remains yet largely uncertain.
Not only are the measurements influenced by a number of factors and parameters like e.g.
workpiece orientation, magnification, edge detection and so on, but also the calibration method
matters greatly. This paper investigates the influence of these factors and parameters and the
calibration method (rescaling and correction) on accuracy and repeatability of the
measurements, using a test object with parallel grooves. The test object is also used to
illustrate how more accurate CMM measurements can be used to calibrate CT measurements
and to compare different calibration and compensation strategies.