Testing surfaces of toroidal or spherical bodies - evaluating light reflected from perpendicularly illuminated strip as body rotates

摘要

A light beam is projected onto the surface of the object (1) under test. The reflected or scattered light received by optical detectors is evaluated. Light is directed perpendicularly at each point within an arc of the surface. Only light from a strip of the surface contg. the arc is fed to a photoelectric detector (27). The test body is rotated during testing only about an axis of symmetry so that the angle of incidence of the illumination does not change. USE/ADVANTAGE - Eliminates some disadvantages of conventional techniques, e.g. need for many optical systems or successive measurements. Even sensitivity of fault detection using reduced illumination. Ball bearings. Glass spheres for producing small optical lenses. Testing surfaces for faults such as scratches, small hollows or projections. Quality of polishing or finish.