Surface inspection of hard to reach industrial parts using low-coherence interferometry

Optical inspection tools based on low-coherence interferometry and specialized for hard to reach industrial parts are presented. A common path configuration using optical fiber components is described. Small diameter probes originally developed for biomedical applications have been specialized for industrial inspection. Probes that can be used with a Cartesian surface scanning system or a cylindrical scanning system are presented. The probes include a reference that makes absolute accuracy measurements easier. Characterization of the internal surface of a worn plasma torch electrode has been realized using that technique. Surface profiling of the barrel of a gun was also performed.