Triangulation and surface inspection in the automatic inspection of drillings and hollows

This paper describes the technical standard today and the invention of our new system. We give an overview about the possibilities of inspection and measurement inside hollows and drillings. A lot of systems exist with several pros and cons. We discuss the different parameters and designs. A special application of our system is the inspection of internal screw threads. Most of the existing measurement systems evaluate the distance between their sensorheads and the reflecting surface out of the intensity of the reflection. But this signal is dependent on the reflection-index of the surface. Normally there is no homogeneous surface. Our new system measures the distance between the sensorhead and the internal surface. We prefer a triangulation technique with a folded beam path. All electrical and optical components are outside the hollow. Only two static plane mirrors mounted on the same support will be inside the sensor-head.