Non-destructive test apparatus with eddy current transducer rotary head and field homogenizing conductive ring for scanning metal test materials
US5187435A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 5, 1991 |
| Grant date | Feb 16, 1993 |
| Priority date | — |
| Expiry date | Jul 5, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/9013
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A rotary head for scanning the surface of elongated test materials (62) by eddy current transducers (60) is additionally provided with means for magnetization of the test material (62) over an intended test range making it now possible to achieve sensitive testing of non-bare ferromagnetic bars and wires, testing for "smeared cracks" where surface has closed above the material separation, and testing of welded austenitic pipes. For the magnetization, parts of the housing (10) as well as a rotating hollow shaft (40) are employed in the conduction of magnetic flux, and special measures are taken for the homogenization of the magnetic field in the test range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.