Other

Armco Inc.

John T Voisine

Wade S Wright

Glenn S Huppi

A system for measuring the relative elongation of portions of a moving steel strip. A number of capacitive sensors positioned above one surface of the moving strip monitor the distance between each sensor and the surface of the strip. This information is processed through a geometrical relationship to calculate the percent relative elongation at one sensing position with respect to another. The calculation may be performed instantaneously, or result from several measurements averaged over a cell length. Provision is made for greater accuracy in cases where waviness of the strip results in the occurrence of more than a predetermined number of waves during a cell length. Wave steepness, wave periodicity, and categorization of relative length information are also provided by the processing.

Non-contact sensing system for determining the relative elongation in a

Method and apparatus for monitoring the flatness characteristic of a moving electrically conducting strip of material by continuously measuring the change in capacitance between the strip surface and a fixed point adjacent the surface. The capacitance is measured by means of a sensor having an active plate surrounded by a guard plate for eliminating stray capacitance, both plates being impressed with a high frequency signal. Changes in capacitance associated with both plates are eliminated while changes in capacitance associated with only the active plate are covered to a voltage proportional to the inverse of the spacing between the active plate and the strip surface. A plurality of the sensors may be spaced across the width of the plate for providing a profile of the strip flatness characteristics. The sensor finds particular application for monitoring and characterizing bottom buckles in steel strip following high temperature annealing.

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Middletown, OH, United States of America

John T Voisine