What is a Coriolis Flow Meter and How Does It Work?

The rapid growth of oil and gas industry requires higher accuracy and wider measurement ranges. As a result, various types of flow meters have been developed, and among all, the Coriolis mass flow meter is reknowned as the most accurate for all industries.

Although the initial purchase price and installation costs of a Coriolis type flow meter are higher, its numerous advantages make it a preferred choice. It provides precise measurements, fast response times, and simultaneous measurement of mass flow, density, temperature and viscosity. Additionally, its low maintenance costs over time further enhance its overall value.

What is Coriolis Flow Meter?

Also known as the Mass Flow Meter or the Inertial Flow Meter, this device functions on the principle of the inertia that is generated by a fluid while flowing through an oscillating tube. This force of inertia results in the twisting of the tube, proportionally to the mass flowrate. The degree of this twist or distortion is captured by sensors in the device and a linear flow signal is given as the output.

How Does A Coriolis meter Work?

The earlier designs of the Coriolis flow meter consisted of a single tube that was in the shape of a curve. However, due to the thinness of the wall of this tube, there were problems with vibration. In modern models, this issue has been eliminated by incorporating two tubes that result in a thicker wall. Additionally, the modified design requires a lesser amount of power and yet is high on durability. There are several shapes and styles of tubes available in the market, each suitable for specific applications. All of them are highly precise and low maintenance.

In this design, the tubes are vibrated in opposite directions by using magnetic coils mounted at the inlet and outlet sections of both the tubes. These magnetic coil assemblies function as sensors. When a magnetic field is generated by these magnets, the coils passing through the field create sine waves. In the idle condition when there is no fluid flowing through the tubes, the inlet and outlet sine waves are in phase.

And when there is fluid flow, the tubes twist causing a phase shift in the sine waves. This twisting is proportionate to the mass of the flowing fluid and the sensors capture this phase shift reading. The phase shift is equal to the time difference between the sine waves and this reading gives the mass flowrate.

Pros of Coriolis Mass Flow Meter

There are a number of advantages of the Coriolis effect flow meter over other types of flow meters. Some of them are as listed below.

✅ Coriolis flowmeter is the most accurate of all flow meters available. Moreover it requires low maintenance since it does't have any moving parts that can cause wear and tear.

✅ They also seldom require calibration.  As Coriolis meter measure mass flow instead of just volume of the fluids, they are suitable for measuring flowrate of materials which are sold by weight and not volume. And in the oil and gas industry value of products like petroleum is measured by heating units (like BTU), thus making the Coriolis flow meter the device of choice to calculate flowrate for such materials.

✅ The mass flow meter gives accurate measurements of fluids and is not affected by the changes in temperature, pressure, speed of flow. This makes it excellent for measuring flowrate of gases which are more prone to be affected by the afore-mentioned changes. It is because of this reason that Coriolis flow meters have gained traction in the oil and gas industry.

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Where to use Coriolis flow meter?

Coriolis flow meter is widely used in industries that require highly accurate flow measurement, such as oil and gas, petrochemicals, food and beverage, pharmaceuticals, and water treatment. It excels in applications involving high viscosity fluids, corrosive substances, and multi-parameter measurements (mass flow, density, temperature, viscosity).

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