Measurement of roundness and run-out with distributed fiber-optics sensors

The quality inspection of products poses a challenge towards existing production metrology techniques in terms of accuracy and speed, especially when it comes to inline or in-process measurements. In this terms, optical metrology proves its capabilities, in particular for sensible and fragile work pieces. For the inspection inside small spaces and cavities or for complex geometries, many optical metrology system are to inflexible or cannot be miniaturized enough. Within this work a set-up for a fiber-optic low-coherence interferometer system is described. Due to the high degree of miniaturization of the sensing probe, the system can be used for demanding measuring tasks like roundness of small drilling holes or the run-out of shafts. Different evaluation measurement are presented, which underline the potential of the described system for highly accurate, non-contact inspection of rotational parts.