Magnograph® II

Commercially available wire rope test instruments have been in regular use in a number of countries for several decades. These instruments reliably reflect current rope conditions, and thereby are helpful in increasing the safety of hoist operations. However, rope failures, or near failures, continue to occur.

At the request of the Canadian Chief Mine Inspectors, the Canadian Government's Mining Research Laboratories of Natural Resources Canada in Ottawa undertook an extensive study of a number of commercially available testers. It was found that while the instruments performed satisfactorily, serious mistakes arose in the interpretation of the data. Consequently, it was decided to proceed with further work aimed at reducing these error sources. Computer assisted instrument setting and data evaluation procedures were considered the best solution.

The first dual function wire rope tester, the MAGNOGRAPHÔ has been improved to take advantage of the latest computer technology. The control console is now based on a laptop computer utilizing the specially developed MagWin software package. The MAGNOGRAPHÔ II-USB allows for the traditional measurements of Loss of Metallic Area (LMA), Local Faults (LF) and Total Change of Metallic Area (TCMA). The TCMA is a measure of the actual ferromagnetic metal in the sensor head instead of the deviation from a reference section of the rope, which an LMA measurement provides The MAGNOGRAPHÔ II-USB sensor head range for metallic area is 0-20kg/m. Since the largest measurable, 64mm diameter wire rope is typically 16 kg/m, out-of-range measurement is impossible.