What Is an Electromagnetic Flowmeter?
An electromagnetic flowmeter is a measuring instrument that can be used in areas where there is a flow of water to correctly measure the velocity of the flow.
Compared to the conventional propeller type, which uses the rotation of a propeller attached to the measuring machine to make measurements, the electromagnetic flowmeter reduces the risk of failure and is easier to handle. It can also handle a wide range of flow velocities, from very fine water flow to high-speed water flow.
An electromagnetic flowmeter consists of a sensor, a tail, and a weight, and the shape of each section prevents the flow from being disturbed, thus enabling correct measurement of flow velocity values.
Uses of Electromagnetic Flowmeters
The electromagnetic flowmeter is used in rivers, lakes, waterways, dams, and other places where water flow occurs to accurately measure the velocity of the water flow.
By using current velocity systems to correctly measure the speed of water flow, we can survey rivers and ocean currents to help design bridges and other structures and to prevent flood damage.
Other applications include the aquaculture industry and research on organisms living in rivers and oceans.
Principle of Electromagnetic Flowmeters
The electromagnetic flowmeter uses the principle of Faraday’s electromagnetic induction to measure the velocity of water currents.
Faraday’s law of electromagnetic induction states that “when an electric conductor moves across a magnetic field, a voltage is generated in that conductor and an electric current flows through it.”
Water flowing through the earth’s magnetic field generates an electric current due to electromagnetic induction.
Therefore, an electromagnetic flowmeter is placed in water, such as in a river or ocean, to form a magnetic field. When water flows through the magnetic field as an electric conductor, electromagnetic induction on the fluid causes an electromotive force to be generated.
Since the electromotive force and the velocity of the water flow are in a proportional relationship, the velocity can be measured from the potential difference.
An electromagnetic flowmeter is generally affected by the presence of high-voltage lines, or by noise from picking up small magnetic fields created by stones or debris containing metals on the river bottom.
However, by narrowing the range of magnetic fields produced by electromagnetic current velocity systems and making them more concentrated and powerful, these can be prevented, thus reducing the disturbance of the values being measured.