NDT.net - August 1999, Vol. 4 No. 8

Magnetic NDT of Steel Wire Ropes

Kazimierz Zawada
Zawada NDT, Tatarkiewicza 8, 41-819 Zabrze, Poland
Email: zawada@silesia.top.pl Fax: ++48 32 2752167 http://www.zawada.z.pl
Kazimierz Zawada, MSc, 1978-1999 at Meraster S.A. (formerly named ZD CNPSS), designer
of wire rope testing equipment and recently director of NDT branch; 1999 founder of Zawada NDT


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 magnetisation 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 sensor detects it as the rope passes trough the sensing head. Other sensor measures total axial magnetic flux in the rope. It provides information about loss of steel due to missing wire, continuous corrosion or abrasion.

Using magnetic method a rope expert have a possibility to estimate the rope condition. In conjunction with visual examination this method may be applied to determine the moment when the rope should be discarded. Various equipment for different application ranges is available.

Permanent magnet method

Limitations of magnetic method




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/DB:Article /AU:Zawada_K /IN:Zawada /CN:PL /CT:ET /CT:magnetic /CT:rope /ED:1999-08