Ultrasonic measuring instrument
US4334431A · kind A · utility
20Cited by
5References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1979 |
| Grant date | Jun 15, 1982 |
| Priority date | — |
| Expiry date | Aug 8, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/02836
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
By detecting the instant of a selected zero-crossing of a received ultrasonic signal rather than relying on the instant the amplitude of that received signal exceeds a predetermined reference amplitude in excess of zero, a transit-time measuring instrument can be realized which is free from the measurement errors normally arising from acoustic signal attenuation in the medium through which it passes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.