Mutual inductance bridge for detection of degradation in metallic components
US6844722B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2002 |
| Grant date | Jan 18, 2005 |
| Priority date | — |
| Expiry date | Feb 27, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/9046
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An inductive bridge circuit using mutual inductances to transform impedances is used for detection of wall-thinning defects in metals. The bridge circuit has a first test coil placed adjacent to a good metal section and a second test coil placed adjacent to a metal to be tested. The bridge circuit compares the inductance in the first coil and inductance in the second test coil to compare wall thinning defects. The apparatus may also include first and second measuring transformers which are connected between the bridge circuit and the test coils where the transformers provide for impedance matching and reduced current requirements in the bridge. The circuit may also include one or more potentiometer circuits connected across the bridge which are used for compensating for imbalance of impedance between the first and second test coils when the coils both have known good metal sections adjacent to them.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.