Eddy current defect simulator and method
US4064452A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 14, 1975 |
| Grant date | Dec 20, 1977 |
| Priority date | — |
| Expiry date | Mar 14, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/9086
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for calibrating an eddy current inspection system is disclosed which utilizes electronic workpiece flaw simulator circuitry for simulating a response produced by a flaw in a ferromagnetic calibration workpiece. The inspection system includes a detector probe which generates an electromagnetic field and is responsive to changes in the electromagnetic field. The workpiece flaw simulator circuitry is positioned in the electromagnetic field adjacent the detector probe. The workpiece flaw simulator circuitry controllably alters the electromagnetic field near the detector probe in a manner similar to a change in the field which would result from a workpiece having a defect of known severity passing through the field. In a preferred embodiment, the workpiece flaw simulator circuitry includes a reaction coil and a resistive loading network which are coupled together to produce inductive and resistive components of impedance in the simulator circuitry. The loading network is adjustable to provide differing predetermined loadings on the reaction coil to the electromagnetic field sensed by the detector probe and thus simulate defects of known severity in the type of wor…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.