The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 07, 2001
Filed:
Dec. 18, 1998
Ray Keech, Stonehouse, GB;
ABB Instrumentation Limited, Huntingdon, GB;
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.