A multi-sensor induction flowmeter reducing errors due to non-axisymmetric flow profiles

The measurement of volume or mass flow through pipes is generally-with almost all types of flowmeters-affected by the flow profile, that is the distribution of fluid velocity over the pipe cross section. To ensure a well-defined flow profile, the flowmeter must be placed sufficiently distant from distorting installations like bends or valves, which increases the installation cost or is even impossible in many applications. With induction flowmeters, the accuracy is independent of the flow profile in the radial direction, but it is influenced by profiles deviating from axial symmetry. In this paper, a novel method for reducing this error is discussed. The method is based on tomographic principles using multiple electrode pairs and two magnetic field components. The pertinent theory is developed, and experimental results are presented.