LMA sensors are located in various places, almost within magnetising circuit or nearby it. This method is limited to the testing of ferromagnetic steel ropes. Although usefulness of magnetic NDT of wire ropes is inestimable, this method should be supplemented with other examinations, especially with visual method. Rope should be tested periodically since its installation date. Magnetic test gives basic information about rope condition.
Instrument indicates defected places on the rope length.
Using magnetic method a rope expert have a possibility to estimate the rope condition. However he should employs also other methods to evaluate the condition of a rope when must say whether the rope should be discarded. Usually the indications should be corrected by calculations, referred to rope construction type and observed deterioration. LF signals generated by internal broken wires and internal wear are sometimes disturbed by signals generated by external non-uniform wear. Internal broken wires accumulated close to each other generate complex signal which amplitude depends on its distribution and number.