The principle of working of the electromagnetic flow meter can be explained by Faraday's life. According to Faraday's law, the voltage generated on a conductor in a magnetic field due to current passing through it is directly proportional to the speed of this conductor. A straight pipe is placed in the magnetic field produced by the field coils. Electrodes in contact with liquids are placed at a 90° right angle to the magnetic field. In this way, voltage, which is the parameters of speed, was measured. The measured voltage is an indicator of the passing flow rate because the area inside the pipe is constant.
Electromagnetic Flowmeters are the most preferred products in the flow measurement with conditions that are conductive of the fluid. It`s preferred in many areas because it has no moving parts in the interior structure, fluid will not corrode and can be selected from materials of the internal coating, not causing loss of pressure and shows excellent performance.
Electromagnetic flowmeters show the instant and total flow amount and accordingly transfer the flow information to the automation system or the current existing process by generating an electrical signal.
The electromagnetic flow meter has a wide range of applications, it can be used in the sectors below:
There is an electromagnetic coil that generates a magnetic field, Inside an electromagnetic flow meter and electrodes that capture electromotive force(voltage). As a result, although it may appear as if there is nothing inside the flow pipe of an electromagnetic flow meter, flow can be measured.
Under Faraday's law of induction, moving conductive liquids inside of a magnetic field generates an electromotive force (voltage) in which the pipe inner diameter, magnetic field strength, and average flow velocity are all proportional.
The amount of flow measured by an electromagnetic flowmeter is not affected by the temperature, pressure, density, or viscosity of the liquid.
Even if there are dirty substances (solids, air bubbles) in the liquid whose flow is to be measured (flow rate will be measured), it is not affected and can make measurements.
There is no pressure loss because the pipe is a closed system.
The measurement security Is increasing because there is no movement part in the system.
Most important point to know when using electromagnetic flow meters is that they should be based on the laws of electromagnetic induction and the liquid passing through the pipe must be conductive. Whether a liquid is conductive or not can be measured with conductivity measuring devices, and there are also simple methods.
You can use a standard test meter when you want to know the presence or absence of electrical connectivity. You place the tester in a mode that measures the resistance value and then both probes are placed in the liquid. It indicates electricity is flowing If the tester's needle moves slightly. When the needle doesn't move at all from its original position, there is no electrical conductivity. It may be thought that it isn’t possible to detect the flow rate of this type of insulating liquids with an electromagnetic flowmeter.
Pure water doesn’t conduct electricity because it is a stable molecule. So how does electricity flow in water as we encounter it in daily life? The secret is that the presence or absence of impurities in water determines its ability to conduct electricity.
Besides H O (water molecules), Ca 2 + (Calcium ions) and Mg 2 + (magnesium ions), are found in water. The terms hard water and soft water are determined by the amount of ions found in water. Because these ions conduct electricity in water, tap water, groundwater, and other ion-rich waters have an electrically conductive property. Since pure water is just H 2 O and does not contain any impurities, it cannot conduct electricity