Method for measuring the wall thickness of a workpiece by ultra-sound
US4838086A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1987 |
| Grant date | Jun 13, 1989 |
| Priority date | — |
| Expiry date | Dec 29, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S73/901
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and an apparatus for measuring the wall thickness of a workpiece by ultra-sound is disclosed. For measuring the wall thickness, it is necessary to determine the time interval between a surface echo occurring during irradiation by ultra-sound and a rear wall echo. According to the present invention, a saw tooth generator generates a saw tooth signal including a sequence of saw teeth when the surface echo occurs. Each of the saw teeth causes a counting pulse to be generated. Upon occurrence of the rear wall echo, the instantaneous amplitude value of the saw tooth signal is measured and the number of counting pulses is recorded by a counter. Each counting pulse defines a constant unit of wall thickness. The amplitude value provides a fraction of such wall thickness unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.