Through the glass brightly

The flat-glass industry is ever more conscious of increasing quality requirements. The automobile industry is currently driving glass-quality specifications, with a need for windscreens with zero defects. Different glass manufacturers impose different standards, but typically they have to detect and reject glass with bubbles and inclusions in the 150–250 μm region. This causes problems for the glass maker who must find these tiny defects in a product that can be 4 m wide and move at 0.5 ms -1 . The only way human examination can deliver this kind of performance is with a team of inspectors across the entire glass "ribbon" width.