Magnetic flowmeters (magmeters) are designed to measure the flow of electrically conductive liquids in a close pipe. With the obstructionless design, there are no moving parts to wear and no pressure drop other than that offered by the section of pipe of equal length and inside diameter. Because the flow path is relatively unobstructed, magnetic flowmeters are well suited to use with high-viscosity fluids and process liquids that contain solids. They can be selected for compatibility with most corrosive of chemicals as well as meet sanitary requirements for food applications.

Magnetic flowmeters do not create pressure drop. Velocity is measured directly, so variations in density do not affect their accuracy. Magnetic flowmeters are free of Reynolds number constraints; they may be used for measuring the velocity of liquids with any flow profile. The output signal is linear and directly proportional to the flow velocity. Magnetic flowmeters can measure flow of conductive liquids in both forward and reverse directions. However, flow in the forward directions develops a voltage that is opposite in phase or polarity from the flow in the reverse direction.