Method and apparatus for magnetic identification and localization of flaws in conductors by canceling the field about the conductor with the field about a flawless conductor
US5109196A · kind A · utility
14Cited by
3References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 5, 1991 |
| Grant date | Apr 28, 1992 |
| Priority date | — |
| Expiry date | Mar 5, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/83
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Flaws in an electrically conductive sample object are detected by cancelling the magnetic field generated by a detection current passed through the sample object by passing the current back through an unflawed field cancelling object placed next to the sample object, and measuring the uncancelled field produced by any flaw, preferably with a superconducting quantum interference device (SQUID) magnetometer. Elongated objects such as tubes and rods are fed through a sleeve which forms the field cancelling object, with the current applied to the elongated member and passed to the field cancelling sleeve through sliding contacts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.