Vortex flow meter transmitter including piezo-electric sensor
US3948098A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 1974 |
| Grant date | Apr 6, 1976 |
| Priority date | — |
| Expiry date | Apr 24, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/3287
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Flow-metering apparatus of the vortex-shedding type wherein an obstruction in a flowing fluid develops a series of vortices which are sensed by a pressure-responsive piezo-electric element to produce an alternating voltage having a frequency corresponding to the fluid flow rate. The piezo-electric voltage signal is processed by electronic circuitry to provide for precise detection of the zero-crossings of the voltage alternations. The resulting frequency signal controls the charge/discharge characteristics of a set of capacitors, with the average charging current corresponding in magnitude to the frequency of vortex shedding. This average current controls an output amplifier in a feedback arrangement to produce a relatively high-powered d-c flow signal over a two-wire transmission line leading to a remote station. In another arrangement, a high-powered pulsating flow signal is developed for transmission over a three-wire transmission line leading to a remote station.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.