The concept for a rotating Lorentz-force flowmeter was developed by J. A. Shercliff in the 1960’s [1, 2]. As shown in Figure 1, the flowmeter consists of multiple evenly-spaced permanent magnets that are installed near the rim of a disc-shaped magnetic yoke. The center of the magnetic assembly is connected to a low-friction bearing that permits rotational motion. When the flowmeter is placed alongside a duct filled with a flowing, electrically-conductive liquid, the resultant Lorentz-force between the liquid and magnets generates a torque upon the flowmeter. During operation, the velocity of the liquid within the duct can be determined by measuring the corresponding angular velocity of the flowmeter.
As described V. Minchenya et al , the torque generated on the flowmeter is a linear function of the relative velocity between the flowing liquid and the magnets. However, in practice, it is very difficult to calibrate the rotating Lorentz-force flowmeter without: A) cumbersome external equipment , B) error-prone analytical or computer modeling [4, 5], or C) redundant flowmeters installed into the flowing system . The remainder of this document will outline a sequence of experimental procedures that can be used to calibrate rotating Lorentz-force flowmeters without any of the aforementioned difficulties or shortcomings.