Acoustic oscillator fluid velocity measuring device
US4003256A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 17, 1975 |
| Grant date | Jan 18, 1977 |
| Priority date | — |
| Expiry date | Nov 17, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/66
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fluid velocity measuring device for the accurate fast measurement of the velocity of a fluid whether liquid or gas using the time of passage of acoustic energy through the fluid as the frequency determining element in a continuous wave oscillator. The frequencies or periods of oscillations of two anti-parallel acoustic paths are used to compute fluid velocity between the electro-acoustic transducers at the ends of the acoustic paths. The device in accordance with this invention may utilize a single reversing acoustic path or two anti-parallel acoustic paths. The velocity resolution can be selected by the operator in accordance with a stated uncertainty principle limiting the ratio of frequency response to velocity resolution. Mode ambiguities due to fluid phase velocity variations are avoided by varying the path lengths. The frequency range of the oscillator is limited by a phase locked loop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.