Electromagnetic flowmeter deriving power from signalling loop current
US6269701A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 18, 1998 |
| Grant date | Aug 7, 2001 |
| Priority date | — |
| Expiry date | Dec 18, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/60
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improvement over conventional electromagnetic flowmeters which signal a measure of flow rate by controlling the current in a current signalling loop (also known as a sensing loop) and in which power for the flowmeter is derived from the current in the signalling/sensing loop. Conventional electromagnetic flowmeters use a standard current range (typically 4-20 mA), in which zero flow is indicated by controlling the current in the loop to a minimum predeterimened value and maximum flow is indicated by controlling the current to a maximum predetermined value. In the improved flowmeter of the invention, minimum flow is signalled by maximum current in the signalling/sensing loop and maximum flow is signalled by minimum current. This has been found to enable improved accuracy to be obtained at low flow rates without requiring complex flowmeter circuitry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.