Giant magnetorestive sensors and sensor arrays for detection and imaging of anomalies in conductive materials
US6150809A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 1997 |
| Grant date | Nov 21, 2000 |
| Priority date | — |
| Expiry date | Sep 18, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/82
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus and method for detecting defects in electrically conductive materials. A detection method and apparatus are provided for using applied magnetic fields to induce magnetic fields in the material under test, and then directly detecting changes in the induced magnetic field attributable to corrosion, cracks, flaws, or anomalies in the material under test. The invention features the use of one or more giant magnetoresistance sensors to detect directly the changes in the induced magnetic field, which changes provoke a response in the giant magnetoresistance sensors in the form of a change in resistance signal. The apparatus may be configured in various ways, including absolute field detection and differential field detection configurations, with either passive or active field compensation, and single sensor or multiple sensor arrays. A plurality of giant magnetoresistance sensors may be disposed upon a single substrate, or on multiple substrates. The invention includes method for performing detection by use of giant magnetoresistance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.