Patent ID: 6915703
Filing Date: 2005-07-12
Classification: G01F

Abstract:
1. A method for determining a flow property of a fluid flowing through a conduit provided with a capacitance meter comprising an upstream annular capacitance sensor, and a downstream annular capacitance sensor, wherein each annular capacitance sensor comprises at least three sensor electrodes, which sensor electrodes are arranged around the circumference of the conduit, the method comprising the steps of: (a) selecting, for the annular capacitance sensor, a set of measurement capacitors, wherein a measurement capacitor is formed by two measurement electrodes, and wherein a measurement electrode consists either of a single sensor electrode or of at least two interconnected sensor electrodes; (b) measuring a capacitance of each measurement capacitor characterized in that the annular capacitance sensor forms an upstream annular capacitance sensor, and in that the capacitance meter further comprises a downstream annular capacitance sensor provided with at least three sensor electrodes, which sensor electrodes are arranged around the circumference of the conduit, wherein the method further comprises the steps of (c) selecting, for the downstream annular capacitance sensor, a set of measurement capacitors; (d) measuring at several moments during a time interval a capacitance of each measurement capacitor of each annular capacitance sensor; (e) determining cross correlations between capacitances measured during the time interval at the upstream annular capacitance sensor and capacitances measured during the time interval at the downstream annular capacitance sensor; and (f) determining the flow property from the cross correlations using a linear operations.