Wire rope damage index monitoring device
US5804964A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 1996 |
| Grant date | Sep 8, 1998 |
| Priority date | — |
| Expiry date | Nov 29, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/82
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A magnetic testing device for obtaining a damaged index of an elongated magnetically-permeable object in real time includes a permanent magnet assembly with spaced-apart poles, a tubular pole piece adapted to surround the object, Hall effect devices placed in the magnetic flux path, a leakage flux sensor installed between the pole pieces, and a real time signal processing unit. The signal processing unit provides local fault (LF) signals generated by the leakage flux sensor, and loss of metallic area (LMA) signals generated by the Hall effect devices. The standard deviations of the LF signals are summed, the root-mean-square of the LF signals is summed, the absolute values of the LF signals are integrated, and the LMA signal is multiplied by a coefficient which is dependent on the object construction. The damage index is then determined using the thus-calculated values. Preferably, when a wire rope is passed through the monitoring device, the damage index is given to the user in a hand-held display means. Preferably, no interpretation is required by the user.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.