Electromagnetic flowmeter utilizing magnetic fields of a plurality of frequencies
US5090250A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 7, 1990 |
| Grant date | Feb 25, 1992 |
| Priority date | — |
| Expiry date | Sep 7, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/60
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electromagnetic flowmeter has first and second magnetic field generating units. The first magnetic field generating unit applies a first magnetic field having a square wave of 4 to 8 Hz to a fluid to be measured. The second magnetic field generating unit applies a second magnetic field having a square wave of 25 to 35 Hz independently of the first magnetic field. A first electromotive force signal induced by the first magnetic field and a second electromotive force signal induced by the second magnetic field are detected by electrodes. A determination circuit determines whether the first electromotive force signal is normal and outputs a determination result. A first signal processing circuit generates a first flow rate signal on the basis of the first electromotive force signal. A second signal processing circuit generates a second flow rate signal on the basis of the second electromotive force signal. A calibration circuit outputs one of the first flow rate signal and the second flow rate signal calibrated by the first flow rate signal as a signal representing a flow rate of the fluid when the determination result represents a normal state, and outputs one of the second flow r…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.