SE357615

1282036 Electrical measuring devices TOKYO SHIBAURA ELECTRIC CO Ltd 26 Sept 1969 [30 Sept 1968 4 Oct 1968] 47497/69 Heading G1N [Also in Division H4] The proportional elongation of a rolled metal strip over a predetermined length L (=(m-1) fix) is measured by disposing a plurality (m) of spaced (by #x) detectors 4 along a line x1 parallel to the direction of movement of, and adjacent but not in contact with, the strip to produce first signals E L1 ,... E Lm representing the distance between respective detectors and portions of the strip surface opposing said detectors, producing second signals #E 1 , ... #E m-1 correspondingto the difference between the first signals from pairs of adjacent detectors, squaring the second signals and adding the squared signals to produce a third signal E n representing the proportional elongation of the strip over the predetermined distance L. As shown, the strip is magnetic and the detectors 4 are electromagnets, the outputs of the respective detecting circuits 8 1 , ... 8 m being applied to non-linear circuits 9 1 , ... 9 m to linearize the outputs of the detectors. The signal E n may be applied to the crown roll of the mill producing the strip to improve the flatness of the strip. A number of parallel rows of detectors may be provided across the width of the strip. The method may alternatively incorporate the use of ultrasonic detectors (see Division H4).