Patent attributes
Methods, apparatus, and systems for flow measurements by alternating magnetic fields are provided. An example alternating magnetic field flowmeter includes a magnetic token movable within a conduit for guiding a fluid flow (conductive or non-conductive) along a flow path, a magnetic field generator configured to generate alternating magnetic fields within the conduit to move the magnetic token along the flow path with a first flow velocity and opposite to the flow path with a second flow velocity, a detector configured to measure respective first and second electrical signals responsive to the alternating magnetic fields, the first and second electrical signals associated with the first and second flow velocities, and a processor configured to determine a flow rate of the fluid based on the first and second electrical signals. The alternating magnetic field flowmeter can include a calibrator configured to manually or automatically calibrate the flow rate with a correction factor.