MAGNETOINDUCTIVE FLOWMETER AND METHOD FOR DETERMINING THE PRESENCE OF A FULLY FORMED ROTATIONALLY SYMMETRIC FLOW PROFILE

摘要

A magnetoinductive flowmeter (1) having a measuring tube (2), which has a measuring tube axis (3), and two measuring electrodes (4, 5) which are arranged diametrically with respect to one another on the measuring tube (2) and at which signals are tapped off in order to determine a flow rate and/or a flow speed, wherein the flowmeter (1) has four further electrodes (8a-11a), each two electrodes (8a, 10a or 9a, 11a) of which are arranged diametrically with respect to one another on the measuring tube (2) and form a second electrode axis (C) and a third electrode axis (F), which axes have a point of intersection with the measuring tube axis (3); wherein the two electrode axes (C, F) are arranged in a manner offset by an angle in the clockwise or anticlockwise direction of less than or equal to π/2 rad with respect to a parallel projection of the first electrode axis (A) on the second cross-sectional plane (Q2), and wherein the magnetoinductive flowmeter has an evaluation unit which is designed to detect a flow profile on the basis of measurement signals (E₂, E₃, E₄, E₅) which are tapped off at the electrodes (8a, 10a and 9a, 11a) of the two electrode axes (C, F), and a method for determining the presence of a fully formed rotationally symmetric flow profile during a flow measurement, and a method for compensating for a measurement error caused by a flow profile during a flow measurement by means of a magnetoinductive flowmeter (1).