Electronic Gaging of Glass Products

The introduction of glass gaging has come about due to the rigid requirements of close dimension for television picture tubes. Prior to the advent of television tubes to the glass industry, the requirement for sophisticated gaging was nonexistent. Television glass, on the other hand, has several very close requirements. The inside surface of the face panel requires a generally spherical shape to be within 0.015 in of true contour, while the periphery of the skirt or edges of the panel must be held to ±0.040, and flatness of the mating surface called ``seal land´´ must be within 0.015 in. Add to all of this the fact that glass scratches easily and chips or breaks readily and so upon the stage enters automatic gaging.