| 摘要 |
A system for measuring a dimension, such as the width, of a hot strip of material on line, particularly steel and glass. The system utilizes two arrays of light sensitive electronically scanned detectors, placed above the hot strip and spaced apart at a distance to permit viewing each edge. Each sensor images the hot strip onto the array of photo sensitive detectors. Using visible and infrared radiation of the hot strip as the energy to expose the detectors, position information of each edge is determined and electronically added to the fixed dimension between the two sensors resulting in a value equal to the total width. The measurement is automatically updated many times per second, as the occasion demands. In order to compensate for varying temperatures of the hot material, the system employs an automatic exposure control which varies the time required to complete a scanning cycle of the electronic detectors in response to changes in the intensity of the lumination of the object to thereby vary the exposure to the detectors.
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