Abstract: A device for measuring the thickness of coatings, wherein a thickness gauge is electrically coupled to a circuit intended to convert the electric signal at the output of said thickness gauge into an electric signal proportional to the thickness of the coating. The conversion circuit comprises a peak detector whose output is electrically coupled to inputs of an automatic measurement range switching unit and a subtractor. Another input of the automatic measurement range switching unit is connected to an output of a reference voltage forming unit, its one output is electrically coupled to another input of the subtractor, another output is connected to an input of an adder, whereas a third output is electrically coupled to an input of a measuring sensitivity control unit. An output of the subtractor is connected to another input of the measuring sensitivity control unit whose output is connected to another input of the adder.

Abstract: A method is proposed by which defects in workpieces are detected magnetically, which method comprises the following steps being performed concurrently: scanning the test surface of a workpiece utilizing magneto-sensitive elements; magnetizing the workpiece perpendicularly to its test surface in the test zone; exciting magneto-sensitive elements; and measuring the tangential component of the magnetic field strength in the test zone. An apparatus for magnetically detecting defects in workpieces according to the proposed method comprises an electrical signal excitation/measuring unit and a detector. The latter has a housing which accommodates a core-type magnet rigidly fixed to it and adapted to be magnetized prependicularly to its working surface which mounts magneto-sensitive elements separated from each other and oriented in a prescribed manner. The elements connect each other and the electrical signal excitation/measuring unit as well.