Entrained Gas Management

Mass Flowmeters – Entrained Gas Management (EGM™)

Entrained Gas Management (EGM™)

Continuous flow measurement with air or gas entrainments

Repeatable 2-phase flow measurement with Entrained Gas Management (EGM™)

Is your measurement with your mass flowmeter interrupted because of gas entrainment in the media?

No matter if your process has unwanted entrained gas or if you need air inside your product, KROHNE’s new Coriolis mass flowmeter with Entrained Gas Management technology has come to the market to ensure stable and continuous measurements. The meter ensures continued operation across a wide range of gas fractions and complex flow conditions.

KROHNE’s OPTIMASS series with Entrained Gas Management (EGM™) functionality is the only range of meters to offer a solution for all flow conditions at a gas volume fraction (GVF) from 0 to 100%.

  • Applications with entrained gas can easily be resolved using OPTIMASS with EGM™
  • Enhanced diagnostics with 2-phase signal
  • Diagnostics in accordance with NAMUR NE 107 requirements
  • Continuous measurement with 0 to 100% gas entrainment
  • Cryogenic and high temperature applications from
    -200 to +400 °C / -328 to +752 °F

New opportunities with EGM™ functionality

The difficulty of in measuring a liquid with entrained gas increases with the fraction of gas. A number of other process factors such as temperature, increases viscosity, pressure, and the relative velocity of the liquid and gas also affect the resulting flow regime.

Today OPTIMASS Coriolis flowmeters with Entrained Gas Management can provide repeatable measurement in situations like:

  • liquids mixed with gas
  • slurries with gases
  • high viscous fluids with gas entrainments
Flow regimes

Entrained Gas Management – the secret of 2-phase flow measurement

Without entrained air, we have the desired regular oscillation of the tubes in the Coriolis mass flowmeter. Air entrained in the liquid dampens this regular oscillation of the measuring tubes, and as the air content increases, it can come to a complete stop.

To overcome this, KROHNE developed powerful control algorithms. These algorithms allow the meter to maintain oscillation and continue to measure even with complex flow regimes. Even during a complete transition from a pure liquid phase to a gas phase and back, i.e. from 0 to 100% gas content, the device will continue to measure without stopping.

Without/with Entrained Gas Management

Mass or density – both is possible even with gas entrainment

Coriolis meters can measure the mass flow and density of any fluid, regardless if it is aerated or not.

Density measurement of single-phase fluids is common practice but for traditional meters it becomes challenging with entrained gas.

In many applications where entrained gas is present, meters with EGM™ show excellent accuracy and repeatability for process control, batching, loading, offloading and transfer measurement.

Mass flow measurement/Density measurement

Typical applications

EGM™ has proven to be very useful in 2-phase flow and batch/loading/empty-full-empty applications in various industries:

EGM Applications – Food & Beverage

Food & Beverage

  • Dairy
  • Ice cream
  • Spinach
  • Chocolate
  • Mayonnaise
  • Pre-dough
  • Tomato purée
  • Meat
  • Syrupv
  • Coffee extract
  • Coolants
  • Highly viscous sugar concentrates and molasses
EGM Applications – Chemical


  • Hydrogen peroxide processing
  • Viscous monomers/polymers
  • Liquid removal from stirred tanks
  • Highly concentrated assets such as fuming HCl or HNO3
  • Polyurethane foams
  • Push to empty tanks
EGM Applications – Oil & Gas

Oil & Gas

  • Drilling fluids
  • Truck loading/offloading
  • Well heads
  • Tank management