Title:
A SYSTEM AND METHOD OFMEASURING CONVECTION INDUCED IMPEDANCE GRADIENTS TO DETERMINE LIQUID FLOW RATES
Document Type and Number:
WIPO Patent Application WO2004059257
Kind Code:
A3
Abstract:
A method and system for measuring the flow rate of a liquid or gas within a flow channel utilizing a centrally located excitation source and a plurality of sensor means. Said excitation means is comprised of a heating element coupled with an alternating current generator. Of the plurality of sensor means, at least one of said sensors is located in a position upstream of the excitation source location, and additionally a second of said plurality of sensors is located in a position downstream of the excitation source. Instantaneous fluid flow rate is calculated utilizing a high gain differential amplifier electrically coupled to said sensors, wherein the convectively induced inductive gradient of the flowing fluid is compared to the symmetrical zero flow induction gradient. Following such a comparison, a voltage signal proportional to the flow of fluid within the channel is derived.
Inventors:
GERHARDT GEOFF C (US)
FADGEN KEITH E (US)
FADGEN KEITH E (US)
Application Number:
PCT/US2003/041348
Publication Date:
May 26, 2005
Filing Date:
December 22, 2003
Export Citation:
Assignee:
WATERS INVESTMENTS LTD (US)
GERHARDT GEOFF C (US)
FADGEN KEITH E (US)
GERHARDT GEOFF C (US)
FADGEN KEITH E (US)
International Classes:
G01F1/684; G01N30/32; G01N30/64; (IPC1-7): G01F1/68
Foreign References:
| US5936156A | 1999-08-10 | |||
| US6085588A | 2000-07-11 | |||
| US3801902A | 1974-04-02 | |||
| US6474155B1 | 2002-11-05 |
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