Coriolis Mass Flowmeters

Coriolis mass flow meters measure the mass flow rate of fluids as they pass through a vibrating tube. This technology provides direct and highly accurate measurements of mass flow, along with density and temperature, making it a comprehensive solution for process control and monitoring.

Coriolis meters operate independently of fluid properties such as viscosity, pressure, and temperature, which enhances their versatility across a wide range of applications. Their ability to deliver three key measurements—mass flow, density, and temperature—from a single device simplifies system design and reduces installation and maintenance costs.

Although the initial investment is relatively high, the superior accuracy, reliability, and multi-variable measurement capabilities of Coriolis mass flow meters deliver long-term value. These features make them especially suitable for critical processes where precise control of material flow is essential.

A Coriolis flow meter measures mass flow using the Coriolis effect. The fluid—liquid or gas—flows through one or more tubes that are set into continuous vibration by an actuator.

When there is no flow, the vibration of the tube is symmetrical, and sensors at both ends detect identical signals. However, once fluid starts to move through the vibrating tube, its mass and inertia create a twist or deflection in the tube. This results in a phase shift between the sensor signals, which is directly proportional to the mass flow rate: the greater the phase shift, the higher the mass flow.

Coriolis meters also measure density. The natural vibration frequency of the tube changes depending on the density of the fluid—denser fluids cause the tube to vibrate at a lower frequency. By analysing this frequency, the meter calculates fluid density accurately.

Thus, a Coriolis flow meter provides direct, simultaneous measurement of mass flow rate and density, using the same sensor. These measurements are independent of fluid properties such as temperature, pressure, and viscosity, making Coriolis meters a reliable and versatile choice for precise flow measurement

The Coriolis effect is the apparent deflection of moving objects—like air or water—when they travel across a rotating surface, such as the Earth. This effect happens because the Earth rotates. While the Earth spins from west to east, different parts of it rotate at different speeds. For example:

The equator moves faster than the poles. As air or fluids move across the globe, their path appears to curve rather than move in a straight line. This “curving” is what we call the Coriolis effect, named after Gaspard-Gustave de Coriolis, a French scientist who first described it in the 19th century.

Key Points:

1. It's not a real force, but an inertial effect caused by Earth’s rotation.
2. In the Northern Hemisphere, it causes moving air or fluids to curve to the right.
3. In the Southern Hemisphere, it curves them to the left.

It explains natural phenomena like wind patterns, ocean currents, and is even considered in technologies like Coriolis flow meters, where mass flow is measured using the same principle of movement deflection.

Coriolis flow meters are widely used across industries such as oil and gas, water and wastewater, power, chemical, food and beverage, and life sciences. They are especially ideal for applications involving low to high flow rates, fiscal custody transfer, and challenging fluid conditions including liquids, gases, slurries, and supercritical fluids. Their ability to directly measure mass flow with high accuracy and repeatability makes them a preferred choice for processes involving varying or unknown fluid compositions.

Coriolis flow meters offer high accuracy across various measurement parameters. For liquids, the accuracy is typically ±0.1% and for gases the accuracy is ±0.5%.

1. Highly Accurate & Repeatable: Delivers extremely precise mass flow measurements.
2. Insensitive to Density Changes: Performance is unaffected by variations in media density.
3. Ideal for Unknown Media Properties: Suitable when the fluid’s properties aren’t fully known.
4. No Need for Straight Piping Runs: Can be installed without long upstream/downstream straight sections.
5. Multi-Parameter Measurement: Many models can also measure density, temperature, and volumetric flow.
6. Reliable for Various Applications: Great for critical dosing, blending, and process control operations.

1. Higher Cost: Typically, more expensive than other flow meter types.
2. Size & Weight: Standard models can be bulky and heavy.
3. Inline Installation Only: Cannot be used as insertion meters—requires full pipe integration.
4. Not Ideal for Dual-Phase Media: Performance can suffer in mixed gas-liquid flow conditions.
5. Application-Specific Limitations: Certain process conditions may not be suitable for Coriolis technology.

All measuring devices are factory calibrated. An additional density calibration is carried out to ensure density or volume flow measurement.

During commissioning, an additional zero calibration must be carried out to adapt the device to the installation and process conditions. The following steps must be carried out by the customer before commissioning::

1. Installing the meter as per manufacturer guidelines.
2. Ensuring flow tubes are completely filled and free of gas bubbles.
3. Defining process conditions (pressure, temperature, density)
4. Closing all shut-off valves downstream of the meter.
5. Warming up the electronics before initiating calibration.
6. Ensuring no flow occurs during zero calibration to avoid false readings.

For recalibration or repairs, the meter may need to be returned to the manufacturer. It is important to thoroughly clean the unit and follow the manufacturer’s return procedure.

Coriolis flow meters typically offer a turndown ratio of 10:1, which means they can measure a broad range of flow rates with high accuracy. This wide range makes them ideal for processes where flow rates vary significantly, ensuring consistent performance across different operating conditions.

Coriolis flow meters generally have a higher initial cost compared to many other flow measurement technologies. However, they offer long-term value due to their durability, lack of moving parts, and high accuracy, which reduces maintenance needs and ensures consistent process performance.
 

The total cost of a Coriolis flow meter depends on various factors, including:

 Line size
Material compatibility (e.g., exotic materials for corrosive media)
Operating pressure and temperature requirements
Application-specific customizations

Instead of relying on base prices found online, which may not reflect your actual needs, we recommend contacting us directly for a tailored quote based on your specific application requirements.

To Know more about it Talk to an Engineer.

Proper installation of a Coriolis flow meter is critical to ensure accurate measurements and long-term performance. While exact installation steps vary by model, here are key considerations:

1. Use qualified personnel for installation.
2. Ensure media compatibility with the meter’s wetted parts.
3. Install the meter where the pipe remains full during operation.
4. Avoid air bubbles, as they can affect measurement accuracy.
5. Maintain sufficient back pressure to prevent cavitation.
6. Minimize vibration and external noise by securely supporting the meter.
7. Do not use the meter to align or support piping.
8. Always perform a zero-point calibration before commissioning.
9. Quick-closing valves should be installed downstream or appropriately distanced upstream to avoid pressure surges.

For detailed instructions Consult an Engineer for more understanding.

KOBOLD, along with its subsidiary Heinrichs, designs, manufactures, and supports Coriolis flow meters for a wide range of applications. With decades of experience, both companies are recognized for their expertise in precision engineering, product quality, and customer-focused solutions.

They also offer specialized manufacturing capabilities for challenging conditions, such as high flow rates, high pressure, and media requiring exotic materials. Heinrichs was the first to develop an OIML-certified Coriolis flow meter for hydrogen fuel applications, showcasing their innovation in the field.

For tailored solutions, technical support, and a reliable performance guarantee, contact us today and get a technical quote.