BLM Magnetostrictive Level Transmitter

The measuring process is triggered by a current impulse. This current produces a circular magnetic field along a wire made of magnetostrictive material. That field is held under tension inside the sensor tube. At the point being measured (liquid level) there is a cylindrical float with permanent magnets. They act as a position transducer whose field lines run at right angles to the impulse magnetic field.

Special features

  • Continuous level measurement on the outside of the bypass
  • 2-wire technology 4 … 20 mA
  • Measured value output via digital interface and a selectable measured value as analogue signal
  • Case from stainless steel (display from glass)
  • Magnetostrictive level measuring instrument with high resolution

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Description

Applications

  • Transmitters for the continuous level measurement of liquids in bypass level indicators
  • Chemical and petrochemical industries, offshore
  • Shipbuilding, machine building
  • Power generating equipment, power plants
  • Pharmaceutical, food, water treatment, environmental engineering industries

Level transmitters with a magnetostrictive, high-resolution measuring principle are used for continuous level measurement of liquids. They are based on determining the position of a magnetic float following the magnetostrictive principle. The level transmitters are mounted on the outside of a bypass level indicator.

This magnetic field of the float tensions the wire. The superposition of these two magnetic fields triggers a mechanical wave in the wire. This is converted into an electrical signal at the end of the wire in the sensor housing by a piezoceramic pick-up.

The measured propagation delay enables the origination point of the mechanical torsional wave to be determined with high accuracy.