Principles and features of Electromagnetic Flow Meter
What is an Electromagnetic Flow Meter?
An electromagnetic flowmeter is a volumetric flow meter which is often known as a magnetic flowmeter (Magmeter, Flowmeter, Flow Measuring Device, Magflow, etc.). This meter works on the principle of Faraday’s law of induction. It’s a transducer that uses the voltage created across a liquid by its flow via a magnetic field to measure fluid flow. It is widely used for the flow measurement of conducting fluids.
These are used for the measurement of drinking water as well as wastewater applications, for any dirty liquids which are conductive or water-based, raw water, etc.
What is the working principle of Electromagnetic Flow Meter?
A set of coils generates the magnetic field in an Electromagnetic Flowmeter. An electric voltage is induced in the conductive liquid as it passes through the electromagnetic field, and it is directly proportional to its velocity. Both the liquid flow direction and the electromagnetic field direction are perpendicular to this produced voltage. The transmitter processes the voltage measured by the electrodes to produce a standardized output signal, which is then shown in an appropriate engineering unit.
In a particular Flowmeter, the flux density of the electromagnetic field and the distance between the electrodes are both constant. As a result, the induced voltage is only a function of liquid velocity.
Physical parameters of liquids such as temperature, viscosity, pressure, density, and conductivity have no effect on the induced voltage as long as the measured liquid’s conductivity is above the minimum threshold level.
What are the features of the Electromagnetic Flow Meter?
Some of the important features of an Electromagnetic Flow Meter are:-
- Various types of Liner & Electrode materials are available as per application requirements.
- The measurement is independent of Viscosity, Density, Dissolved/Un-dissolved solids, pressure, or temperature of the flowing liquid as long as it maintains certain minimum conductivity.
- It has a full-bore flow and hence the meter does not obstruct the flow of the liquid being measured.
- No pressure drops and hence the results of Electromagnetic Flow Meters are more accurate.