METHOD FOR DETECTING PINHOLE DEFECTS IN FOIL MATERIAL

摘要

A system for detecting the number of pinhole defects in any given segment of advancing foil material. Particularly a narrow width ultra-violet light source and corresponding ultra-violet and photomultiplier unit, as well as associated circuitry for shaping and counting electrical pulses, corresponding to the diameter of the pinhole defects. The system distinguishes from the prior art in that it makes possible the detection of holes in a material having a large density of holes as well as discriminating as to the number of given defects in several different sizes or threshold categories.