Basics of Coriolis Flow measurement?

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Coriolis Flow Measurement

Operating Principle -

The operating principle of Coriolis flow mass flow meter is based on the force exerted by the Coriolis acceleration of a fluid.

Construction of Coriolis Flow meter -

The flow meter consist of a vibrating tube in which the Coriolis acceleration is created and measured.

Drive System - The drive system typically involves the use of magnet and coils. Power is supplied to the coil to vibrate the tubes at their natural drive frequency.

Sensor system - The sensor can also consist of a magnet and coil as well as other designs such as optical sensor. The time delay between the signal from sensor A and sensor B are used to determine the mass flow rate through the tubes.

How it works ?

The flow tube is designed to and build to have predictable vibration characteristics.

Drive assembly connected to the center of the tube causes the tube to twist. This vibrate the tube. Position sensor coils on each side of the flow tube sense the twisting. Since the frequency of vibration of the tube varies with the density of the fluid inside the tube,the computer inside the electronic unit of the coriolis flow meter can calculate the density value. Coriolis flow meter canbe used on virtually any liquid or gas that flows at a mass great enough to operate the meter.

Advantages-

Higher output rates
Reduced maintenance cost
High accuracy for density
Density measured under pressure
Volumetric flow rate from mass and density
Coriolis is unaffected by vibrations in process condition,conductivity,Liquid or gas state,Density,Temperature,Viscosity.

Disadvantages -

Calibration is expensive and time consuming.