Acoustic flowmeter with envelope midpoint tracking
US4480485A · kind A · utility
66Cited by
8References
17Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 1, 1982 |
| Grant date | Nov 6, 1984 |
| Priority date | — |
| Expiry date | Oct 1, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/667
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An acoustic burst with a predetermined amplitude envelope is triggered by a square wave signal and transmitted upstream or downstream to a transducer connected to an adaptive control system which tracks the midpoint of the received envelope. The received signal is rectified and fed via a polarity reversing circuit controlled by the square wave to an integrator whose output level controls the frequency of the square wave. The burst transit time is measured to the next zero crossing of the received signal following the half cycle transition point of the square wave.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.