Electromagnetic flow meters

Electromagnetic flow meters measure the volume flow of conductive liquids in a closed pipe. They enable bidirectional flow measurement with high accuracy in a wide range of flow velocities (0.025 to 10 m/s). The minimum required conductivity of the measured medium is 5 μS/cm. The evaluation unit allows to display the measured values on the display and to change a large number of operating parameters of the meter using the keyboard. They are used in water, water industry, energy, food, chemical and petrochemical industries and other industries.

Main advantages of electromagnetic flow meters:

• High measurement accuracy over a wide range of measured values

• High reliability and stability with minimal maintenance requirements

• Bidirectional measurement

• No hydraulic losses in the pipeline

• Compliant with sanitary standards

• Possibility of remote transmission of measured data

• ATEX / IECEx certificate (type FLONEX FXx11x)

Use of electromagnetic flow meters

Thanks to their advantages and versatility, electromagnetic flow meters are suitable for measurement in almost all industries, especially water, chemical, petrochemical, food (sanitarians) and energy industries. They are also applied to the measurement of liquids containing solid parts or non-homogeneous mixtures. For special measurement of liquids with abrasive particles, it is convenient to use an electromagnetic flow meter with a special stone lining. Electromagnetic flow meters meet demanding requirements on accuracy, reliability and long-term stability of measurements. They allow the measurement of the medium flow in both directions. The measurement of the medium flow takes place in a contactless manner, without mechanical moving parts and does not affect the hydrodynamic conditions in the pipeline in any way.

Measurement principle

The function of electromagnetic flowmeter is based on the Faraday induction law. The meter sensor consists of a non-magnetic electrically non-conductive tube and two inbuilt electrodes that pick up the induced voltage in a plane perpendicular to the direction of the magnetic power lines. The magnetic field is generated by electric current flowing through two coils wound on the tube. The flow of the conductive liquid through the tube gives rise to induced voltage U proportional to the magnetic induction B, flow velocity v and the length of the virtual conductor l:

u = B x l x v

where:

• u = induced voltage
• B = magnetic induction
• l =  distance between the measuring electrodes
• v = flow velocity of the measured liquid