{"id":6501,"date":"2019-07-29T15:19:46","date_gmt":"2019-07-29T19:19:46","guid":{"rendered":"https:\/\/assuredautomation.com\/news-and-training\/?p=6501"},"modified":"2023-02-14T14:18:48","modified_gmt":"2023-02-14T19:18:48","slug":"magnetic-flow-meter-basics","status":"publish","type":"post","link":"https:\/\/assuredautomation.com\/news-and-training\/magnetic-flow-meter-basics\/","title":{"rendered":"Magnetic Flow Meter Basics"},"content":{"rendered":"\n
\"Magnetic<\/a><\/figure>\n\n\n\n

A magnetic flow meter, also referred to as mag flow meter or magmeter, is a volumetric flow meter that measures liquids or liquid slurries that have a minimum conductivity of 5 \u00b5S\/cm.  Magnetic flow meters will typically not work with hydrocarbons, distilled water, non-aqueous solutions and non-conductive solutions. <\/p>\n\n\n\n

Magnetic flow meters utilize Faraday’s Law of Electromagnetic Induction<\/a> to determine the velocity of a liquid flowing in a pipe.  Magnetic flow meters consist of a nonmagnetic flow tube, liner, electrodes and electromagnets to generate a magnetic field. In magnetic flow meters, a magnetic field is generated and channeled into the liquid flowing through the pipe. <\/p>\n\n\n\n

Operating according to Faraday’s\nLaw, signal voltage (E) is dependent on the average liquid velocity (V) the\nmagnetic field strength (B) and the length of the conductor (D) which in this\ninstance is the distance between the electrodes.<\/p>\n\n\n

Faraday’s Formula<\/strong>
E<\/strong> is proportional to V<\/strong> x B<\/strong> x D<\/strong> where:\u00a0

E<\/strong> = The voltage generated in a conductor
V<\/strong> = The velocity of the conductor
B<\/strong> = The magnetic field strength
D<\/strong> = The length of the conductor<\/p>\n\n

\"Mag<\/p>\n\n\n

The liquid flowing through the pipe is the conductor, and electromagnetic coils surrounding the flow tube generate the magnetic field. The signal is sensed by the two electrodes embedded on opposite sides of the flow tube. The flow signal at the electrodes is directly proportional to the flow velocity, the intensity of the magnetic field, and distance between electrodes.<\/p>\n\n\n\n

\n\nMagnetic flow meters do not require much upstream and downstream straight runs so they can be installed in relatively short meter runs. \n\n<\/p>\n\n\n\n

Advantages of using Electromagnetic Flow Meters<\/strong><\/h3>\n\n\n\n

The main\nadvantages of using magmeters is that they feature an obstruction-free design with no moving parts\nwhich eliminates flow impediment, requires less maintenance and can be used\non very large line sizes.  Accuracy over a wide flow range can be\nas good as \u00b10.5%<\/p>\n\n\n

\"Mag<\/div>\n\n\n

Mag meters perform extremely well in many municipal and processing applications and is the meter of choice for measuring conductive liquids such as water or slurry. Magmeters also have the advantage of being able to measure both very low flows and very high volume flow rates.<\/p>\n\n\n\n

Disadvantages of using Magnetic Flow Meters<\/strong><\/h3>\n\n\n\n

Magnetic flowmeters\nare only effective on conductive fluids, and materials such as unmixed\nhydrocarbons and gases cannot be measured. However, magnetic materials\nthemselves may also present problems, as hydrodynamic effects can alter the\nnormal flow pattern and disturb the velocity rate enough to interfere with\noperations. Depending on their size and capacity, magnetic flowmeters can be\nrelatively heavy, and those with higher corrosion and abrasion resistance can\nbe expensive.<\/p>\n\n\n\n

Typical Industries Where Magnetic Flow Meters are Used<\/strong><\/h3>\n\n\n\n