Remote width measurement system.

摘要

A remote width measurement system for determining the extension of a variation in optical density is disclosed. An expanded laser beam is translationally displaced by a rotating biplanar glass piece (20) for sweeping the width of a variation in optical density (22). The laser signal is then detected and the resulting signal is processed through a current-voltage converter (28), a positive and a negative peak follower circuit (32, 34), and a comparator (46). The comparator output (50) is convoluted with a 800 kHz signal in an AND gate (58) and its output (56) is fed to a counter (62), which in turn feeds a display (64) indicating the width of the variation in optical density.