Method and apparatus for detecting shape of flat products

An apparatus for detecting the shape of flat products, comprising:

• a plurality of exciters provided at a distance from the surface of the product being examined at locations along the width thereof;
• a plurality of detecting heads, each consisting of a plurality of deflection detectors, each of said deflection detectors being coupled with an exciter and operatively positioned for detecting deflection of the flat products;
• a rectangular wave generator coupled to said exciters;
• a plurality of signal transmitters, each connected to one of said deflection detectors;
• a plurality of signal processing circuits, one coupled to each of said transmitters, each signal processing circuit consisting of a device for changing polarity, an integration circuit, a sample-holding circuit and a timing signal generating circuit, said device for changing polarity coupled to receive signals from the respective transmitters and changing the polarity of detecting signals sent from said signal transmitters, said integration circuit coupled to said device for changing polarity and integrating the value of detection signals sent from said device for changing polarity, said sample-holding circuit coupled to said integration circuit and storing tension signals calculated in said integration circuit, and said timing signal generating circuit being connected with said rectangular wave signal generator, said device for changing polarity, said integration circuit and said sample-hold circuit for respectively controlling the timing change for said device for changing polarity, reset-timing for said integration circuit and sample-hold-timing for said sample-holding circuit.