Non-contact feature detection using ultrasonic Lamb waves
US7963165B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 25, 2007 |
| Grant date | Jun 21, 2011 |
| Priority date | — |
| Expiry date | Mar 10, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/2634
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus and method for non-contact ultrasonic detection of features on or within the walls of hollow pipes are described. An air-coupled, high-power ultrasonic transducer for generating guided waves in the pipe wall, and a high-sensitivity, air-coupled transducer for detecting these waves, are disposed at a distance apart and at chosen angle with respect to the surface of the pipe, either inside of or outside of the pipe. Measurements may be made in reflection or transmission modes depending on the relative position of the transducers and the pipe. Data are taken by sweeping the frequency of the incident ultrasonic waves, using a tracking narrow-band filter to reduce detected noise, and transforming the frequency domain data into the time domain using fast Fourier transformation, if required.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.