A magnetic flow meter (mag meter, electromagnetic flow meter) is a transducer that measures fluid flow by the voltage induced across the liquid by its flow through a magnetic field.
A magnetic field is applied to the metering tube, which results in a potential difference proportional to the flow velocity perpendicular to the flux lines.
The physical principle at work is electromagnetic induction. The magnetic flow meter requires a conducting fluid, for example, water that contains ions.
ELECTROMEGNETIC FLOWMETER are mainly used in various industries like STP, ETP, WTP, Borewells, and for conductive liquids for measuring the flow rate and totalizer.