Precision nondestructive testing of metals
US4667149A · kind A · utility
26Cited by
5References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 31, 1983 |
| Grant date | May 19, 1987 |
| Priority date | — |
| Expiry date | May 31, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/041
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A large number of applications exists for measuring the resistivity or other properties of ferrous and nonferrous metals, including matching alloys to ensure weld compatibility and measuring weld size to estimate weld strength. In the present invention, a DC current-reversal technique allows for accurate electrical measurement with a 4-point probe, alleviating problems due to surface potentials, thermal effects, and eddy currents that previously rendered such measurements inaccurate. Estimates of thermal conductivity, flaw size and location, among others, can also be obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.