DEVICE FOR DETECTING INHOMOGENEITY WITH SHARP BOUNDARIES OF A THIN OBJECT, AND A METHOD FOR USE THEREOF Russian patent published in 2020 - IPC G01B7/06 G07D7/26 

FIELD: nondestructive inspection technique.

SUBSTANCE: invention relates to the field of nondestructive inspection of thin objects. Capacitive sensor for detecting inhomogeneity of a thin object having sharp boundaries comprises a plurality of measurement capacitors arranged one after the other along an axial line of the sensor perpendicular to the direction of movement of the thin object. Each capacitor includes first and second plates separated by a gap of a predetermined width, with formation of a thin object propagation path in said gap. Every two measuring capacitors located directly next to each other form a differential pair, and measuring circuit of sensor is made with possibility of obtaining differential response for each differential pair, which is determined by difference of capacitors of capacitors, which make differential pair. Geometric centers of gravity of sensitivity zones of measuring capacitors immediately adjacent to each other represent the vertices of saw-tooth polygonal line, wherein the measurement capacitance sensitivity zone is determined by the mutual overlapping region of the first and second plates. In the process of separate measurement, a differential response is obtained for all pairs of the sensor at each displacement of the thin object by a predetermined pitch, thus forming a capacitive image of the thin object, consisting of lines, where series-arranged pixels of each line correspond to differential responses of series-arranged differential pairs of sensor, and each line corresponds to successively produced separate measurement, and in the specified manner the above capacitive image is analyzed for heterogeneity detection.

EFFECT: high reliability of detecting an inhomogeneity.

11 cl, 6 dwg