Industrial X-ray computed tomography is a holistic measurement technique for dimensional metrology. However, the relatively long measurement time is a hindrance to its application. A possibility to reduce measurement times, the continuous scan mode, is characterized in this work. The question is how much the time reduction impacts the accuracy of the dimensional measurements. The core result of the paper is an estimate of the effect along with experimental proof that this estimate is reasonable.

The framework of the single point uncertainty presents a methodology to determine the local measurement uncertainty for a measurement setup. The targets of the investigation were spur (involute) steel gear wheels using a CMM in scanning mode in combination with a rotatory table, as well as a single scan of the complete gear profile without the use of a rotatory table, using the free-form scan CMM functionality. Both methods were examined with respect to their obtained single point uncertainty.

This paper aims to demonstrate the complete workflow of the determination of the local measurement uncertainty and its components (systematic and random measurement error) for a given measurement task. It was shown for an optical measurement setup in combination with an industrial X-ray computed tomography reference measurement system that different necessary colouring methods of polymer gear wheels have a measurable influence on the local distribution of the measurement uncertainty.