Glossary Updates12 new terms added to the glossaries · October 2, 2026, 22:44 CEST
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Glossary · Sensors and measurement

Magnetic flowmeter

Also known as: Electromagnetic flowmeter, Magmeter, MID

German: Magnetisch-induktiver Durchflussmesser

In process instrumentation, a magnetic flowmeter is a flowmeter that measures the volume flow of electrically conductive liquids using Faraday's law of induction: the liquid moving through a magnetic field induces a voltage proportional to its velocity.

  • Sensors
  • Process industry

In one sentence

A magnetic flowmeter measures the volume flow of conductive liquids by the voltage induced in the liquid as it flows through a magnetic field.

Example

Magnetic flowmeters measure the water and wastewater flows in a treatment plant without any parts that obstruct the pipe.

How it applies

  • Engineering: The medium must have a minimum electrical conductivity, so the principle does not work for gases, oils or demineralized water below that limit. The open measuring tube causes practically no pressure drop.
  • Installation: The pipe must be completely filled. Straight inlet runs and correct grounding or grounding rings are needed; liner and electrode materials must suit the medium.
  • Maintenance: Deposits on electrodes can disturb the measurement. Many devices provide diagnostics for empty pipe and electrode condition.
  • Documentation: State the minimum conductivity and installation conditions in the operating instructions, and record the calibration factor of each sensor.

Magnetic flowmeter vs. Coriolis flowmeter

A magnetic flowmeter measures volume flow of conductive liquids. A Coriolis flowmeter measures mass flow and density and works with non-conductive media and gases.

By knowledge.aitechdoc.world · Published September 26, 2026 · Last reviewed

Source: AI TechDoc Knowledge editorial definition, based on flow measurement practice

Definitions follow the cited standards and specifications. Where a source is a copyrighted publication, such as an ISO, IEC or EN standard, the definition is a close paraphrase, not a verbatim quotation, so as not to infringe copyright. We recommend reading the original publication. The sections “How it applies” are editorial commentary by AI TechDoc Knowledge and are not part of any standard.

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