• Industrial X-Ray and Allied Radiographers (I) Private Limited

Magnetic Flux Leakage Testing Of Steel Wire Ropes

Magnetic flux leakage (MFL) is a magnetic method of non-destructive testing that is used to detect corrosion and pitting in steel structures, most commonly pipelines and storage tanks. The basic principle is that a powerful magnet is used to magnetize the steel at areas where there is corrosion or missing metal, the magnetic field "leaks" from the steel. In MFL tool a magnetic detector is placed between the poles of the magnet to detect the leakage field. Magnetic NDT of wire ropes has been in regular use in a number of countries for inspection of hoisting ropes in deep mines and inspection of ropeways. Recently used method is based on magnetization of the rope with permanent magnets and detection of the changes of magnetic field around the rope and total magnetic flux. Discontinuity in the rope, such as broken wire or corrosion pit creates radial magnetic flux leakage and the sensor detects it as the rope passes trough the sensing head. Other sensor measures total axial magnetic flux in the rope