Ultrasonic doppler flow meter
US4905206A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1989 |
| Grant date | Feb 27, 1990 |
| Priority date | — |
| Expiry date | Jun 20, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S15/584
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A flow meter, in which pulsed continuous ultrasonic wave is transmitted towards an object at predetermined intervals T to obtain a phase vector from a reception signal of wave reflected by the object and which calculates a Doppler frequency from the average value of phase differences between phase vectors at the sampling interval T to obtain a signal indicating the speed of the object, comprising a phase difference calculator by the auto-correlation method, by which a plurality of phase difference vectors indicating phase differences between phase vectors are added, the argument of the sum vector thus obtained representing the average phase difference, or a phase difference calculator by the 2-axial-component method, by which a phase difference is divided into 2 axial components, a cosine value and a sine value, and the average phase difference is obtained by using the average value for each of the components, and a phase difference calculator by the phase difference averaging calculator, by which a plurality of phase differences are added, as they are, to obtain the average thereof, in order to obtain a phase difference average value having small errors by switching them.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.