Electromagnetic acoustic transducer (EMAT) inspection of cracks in boiler tubes
US6282964A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Sep 17, 1999 |
| Grant date | Sep 4, 2001 |
| Priority date | — |
| Expiry date | Sep 17, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/2634
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An EMAT device for non-destructive inspection of the surface of a tube for cracks using acoustic surface waves includes a pulsed magnet having an active surface for facing the surface of a tube to be inspected. A receive emat coil is on the active surface and a transmit emat coil is on the opposite surface of the receive coil. The transmit emat coil has a scan surface for scanning over the tube surface. A transmitter for generating and transmitting an RF signal to the transmit emat coil is provided for generating a transmitted acoustic wave signal along the tube, the transmitted wave creating a reflected acoustic wave if a crack in the tube is encountered, the reflected wave generating a reflection signal in the receive emat coil. A receiver is connected to the receive emat coil for receiving the reflection signal. A digital computer is connected to the receiver for receiving and for processing the reflection signal and a display displays information about a crack in the tube which created the reflected acoustic wave and resulting reflection signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.