Abstract: A method for determining the flatness of a material strip and a device for performing the method. The method and device solve the technical problem of calculating the strip elongation from values of the strip contour and thus determining the flatness of the material strip. This problem is solved according to the present invention by a method in which, from the changes of slope values measured at a plurality of measurement points, the wavelength and phase of these changes are calculated. Therefrom there is calculated the position of at least one extremum, at which the measured slope values have only a transverse component. The slopes are summed to calculate a contour, from which the amplitude is calculated. The strip elongation as a measure of the flatness of the material strip is then determined from the wavelength and amplitude.

Abstract: A process for the determination of the thickness transverse profile and the thickness longitudinal profile of a running material strip.

Abstract: Measuring signals are compared with an output of an integrator, and the difference is fed to a threshold device having suppression ranges corresponding to the noise band. The threshold device output drives the integrator. The suppression ranges are controlled in response to actual and/or anticipated noise.