Magnetic

A mag flow meter operates according to the electromagnetic measurement principle. According to Faraday’s Law of electromagnetic induction, a voltage is induced in a conductor moving through a magnetic field. The electrically conductive medium acts as the moved conductor. The voltage induced in the medium is proportional to the flow velocity and is therefore a value for the volumetric flow. The flowing media must have a minimum conductivity.

The induced voltage is picked up by two sensing electrodes, which are in contact with the medium, and sent to an amplifier.
The flow rate is calculated based on the cross sectional area of the pipe. The measurement is independent of the process liquid and its physcial properties such as density, viscosity and temperature