FELSOKNINGSANORDNING FOR KONTROLL AV LANGSTRECKTA FERROMAGNETISKA ALSTER SAMT KRETS FOR BEHANDLING AV UTSIGNALER FRAN FELSOKNINGSANORDNINGEN

摘要

The invention relates to the nondestructive testing of materials. The novel defectoscope comprises a U-shaped magnetising device whose pole shoes (2) have openings (3) for the workpiece (4) under test to pass through. It also comprises a sensing head (8) having a concentrator constructed in the form of two rings (9) and (10) having a trapezoidal cross section. The rings (9) and (10) are arranged with their smaller bases facing one another. Disposed between the rings (9) and (10) is a Hall pickup (11) whose output signal carries the information relating to the defect detected. According to the invention, the sensing head (8) is disposed in a sealed housing (13) made of nonmagnetic material in such a way that it is offset with respect to the magnetically neutral zone of the magnetic field in the direction opposite to the direction of travel of the workpiece (4) under test. The novel circuit arrangement for evaluating the output signal of the defectoscope comprises an amplifier (16) connected to a recording device (20). According to the invention, the circuit arrangement is provided with a capacitor chain (17) connected between the output of the Hall pickup (11) and the input of the amplifier (16). The noval circuit arrangement also comprises an adjustable voltage divider (18) which is inserted in the supply circuit of the amplifier (16), whose inverting input ... Original abstract incomplete.