ELECTRO MAGNETIC FLOW METER WORKING PRINCIPLE
Electromagnetic Flow Meters, simply known as magnetic flow meter is a volumetric flow meter which is ideally used for waste water applications and other applications that experience low pressure drop and with appropriate liquid conductivity required.
The device doesn’t have any moving parts and cannot work with hydrocarbons and distilled water. Magnetic flow meters are also easy to maintain.
Principle of Magnetic Flow Meter Based on Faraday’s Law
Magnetic flow meters works based on Faraday’s Law of Electromagnetic Induction.
According to this principle, when a conductive medium passes through a magnetic field B, a voltage E is generated... which is proportional to the velocity v of the medium, the density of the magnetic field and the length of the conductor.
magnetic flow meter theory
In a magnetic flow meter, a current is applied to wire coils mounted within or outside the meter body to generate a magnetic field. The liquid flowing through the pipe acts as the conductor and this induces a voltage which is proportional to the average flow velocity.
This voltage is detected by sensing electrodes mounted in the Magnetic flow meter body and sent to a transmitter which calculates the volumetric flow rate based on the pipe dimensions.
Mathematically, we can state Faraday’s law as
E is proportional to V B L
E is the voltage generated in a conductor, V is the velocity of the conductor, B is the magnetic field strength and L is the length of the conductor
Magnetic Flow Meter Animation
Basically when the conductive liquid flows through the magnetic field, voltage is induced. To measure this generated voltage,...which is proportional to the velocity of the flowing liquid, two stainless steel electrodes are used which are mounted opposite each other.
The two electrodes which are placed inside the flow meter are then connected to an advanced electronic circuit that has the ability to process the signal. The processed signal is fed into the microprocessor that calculates the volumetric flow of the liquid.