Electromagnetic flow meter
US4773274A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 1987 |
| Grant date | Sep 27, 1988 |
| Priority date | — |
| Expiry date | Feb 27, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/60
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electromagnetic flow meter for measuring the flow rate of a fluid by applying to the fluid a magnetic field generated with an exciting current and measuring the resulting signal voltage generated at a pair of electrodes; wherein the exciting current comprises two frequency components which are lower and higher than the usual commercial frequency and the signal voltage comprises two frequencies which are discriminated so that a higher frequency is extracted as a first output and a lower frequency is extracted as a second output, through a low pass filter having a large time constant. A predetermined operation, such as addition, zero correction, response correction, etc, is carried out on the first and second outputs to produce a flow rate output. The invention has quick response, stable zero point and reduced susceptibility to noises.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.