Key characteristics
Robust operation under typical multiphase disturbances
Included in all electromagnetic flowmeters with the IFC 400 converter
Stability of operation even when gas bubbles or solid particles disrupt the media properties
Helps avoid measurement dropouts in dynamic or challenging flow conditions
Multiphase disturbances – unavoidable or unintended?
Gas inclusions, entrained air, and solids in the medium, as well as electromagnetic disturbances may occur intentionally as part of the process or unintentionally as side effects of operations. Common causes include:
Aeration and mixing processes
Pump behaviour (e.g., cavitation, leakage)
Filling, draining, or flushing operations
Turbulence or poor flow conditioning
Sediment, fibres, or light solids in the medium
These disturbances can change the media properties and interrupt the sensing field of electromagnetic flowmeters, making them prone to signal instability and temporary measurement failure.
How multiphase disturbances affect electromagnetic flow measurement
Conventional electromagnetic flowmeters rely on a stable, fully filled pipe with a homogeneous liquid to generate a usable measurement signal. When gas bubbles, air slugs, or solid particles pass through the measuring section, the induced voltage signal can fluctuate heavily — sometimes leading to a complete signal collapse.
Typical effects include:
Sudden jumps in the measurement value
Increased noise on the signal
Temporary loss of measurement
Device fallback into error mode
These interruptions can disrupt process control, batch operations, or continuous monitoring tasks.
To address these challenges, KROHNE has implemented advanced control algorithms in the IFC 400 converter to help maintain device operation during such disturbances.
Continuous operation under dynamic flow conditions
Multiphase flow conditions can vary widely depending on operating parameters such as pressure, velocity, viscosity, temperature, or the amount of entrained material. Even under these conditions, MPO supports continuous device operation without measurement dropouts.
While MPO does not compensate or correct measurement values, it keeps the flowmeter from stopping or entering failure mode during typical multiphase disturbances. The operator maintains visibility of the process and can continue running the plant without interruption.
Benefits
MPO provides several practical advantages for your plant and processes:
Reduced risk of measurement failure during common gas or solids disturbances
Improved process stability during start‑up, shutdown, flushing, or filling sequences
Fewer unexpected standstills caused by momentary gas entrainment or solids passing through the line
Increased robustness of electromagnetic flow measurement in real‑world conditions
No additional hardware needed — included with the IFC 400 converter
Typical applications for electromagnetic flowmeters with MPO
Chemical industry
Mixing and blending processes
Reactor feed and discharge lines
Utilities with variable or aerated liquids
Food & beverage
Aerated products
Cleaning cycles with fluctuating filling levels
Liquids containing pulp, fibres, or light solids
Water & wastewater
Pumping stations
Raw influent and sludge transfer
Networks with entrained air from topology or pipe conditions
Energy sector
Cooling and utility circuits
Condensate return with air pockets
Flushing and fill‑drain operations
MPO is particularly beneficial where flow conditions cannot be fully controlled or where fluctuating media composition is part of daily operations.
