Method and apparatus for measuring thickness of layer using acoustic waves
US5663502A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Oct 18, 1995 |
| Grant date | Sep 2, 1997 |
| Priority date | — |
| Expiry date | Oct 18, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/048
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Ultrasonic waves from a transmit device are transmitted to an object subject to measurement. A surface reflected wave propagated in a contact medium and reflected at the surface of a tube and bottom surface reflected waves passing through an oxidation layer on the tube and reflected at the inner surface of the tube are convened into electric signals. A feature extracting part 5, in consideration of a correlation relationship of energy with respect to the frequency of a received signal, based on the received signal of ultrasonic waves converted to electric signals, extracts a signal feature data determined beforehand which has a strong correlation relationship with the thickness of a measured part. Based on the extracted signal feature data, a thickness conversion part references a relationship storage part which has stored therein beforehand a function that shows a relationship between the signal feature data and the thickness of the oxidation layer, and obtains the thickness of the oxidation layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.