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Exploring why Coriolis Technology is used in Flow Metering

Tuesday, March 21, 2023

We would like to introduce Coriolis Flow Meters, these are used on liquids, slurry’s, liquids with solids, vapours, and gases! How can one device be used on different fluids (Gas or Liquids)? Coriolis technology is independent on the fluid properties that travels through the meter sensor tube. Whereas other technologies for example Thermal-based Technology which is used in many Flow devices require the liquid or gas properties to be known. Further the tube is not an intricate sensor type with laminar flow elements with can block, the Coriolis is a tube with a constant inner diameter selected for the process requirements.

Coriolis techniques of measurement are covered in my earlier article which can be found here: How does a Coriolis Meter work

Rheonik RHM02 Small Coriolis Flow Meter

Low Flow Rheonik Coriolis Flow Meter: Flow range between 25g/min to 10kg/min

Rheonik RHM 160 Large Coriolis Flow Meter

High Flow Rheonik Coriolis Flow Meter: Measures up to 30000kg/min of flow

Flow ranges

  • Min Flow Range: 0.002 kg/min up to 1.2 kg/min, Smallest model
  • Max Flow Range: 250 kg/min up to 30000 kg/min, Largest Model

Pressure ratings

The other advantages of Rheonik Coriolis from the two listed above (Any Fluid, elimination of blocking) are that very high pressures can be used, this is appealing to research as well as Industrial applications. With well over 1000Bar being possible and in the RHM015 range 1481 Bar (21480PSI) can be achieved with the appropriate materials of construction. This is incredible to think that accurate flow measurement in a tube that vibrates and the vibration and twist is measured with an optical sensor at these very high pressures.

Temperature Ratings

What’s more impressive is combing the pressure with the temperature range available for the fluids flowing. The temperature range can be used on Cryogenic application to high temperature process. Examples again sticking with the RHM 015, -196 to + 210 Deg C (-320 to +410 Deg F) - there are options for an extension on the range however we will cover the core range here.

Accuracy and Turn Down

With these extremes of pressure and temperature overflow ranges that incorporate many models, how accurate would the best be? The advance in technology and with the attention to quality products Rheonik meters are highly accurate compared to any meter and generally far superior to other technologies. Often Coriolis is the only option that can meet the customers process demanding requirements.

Depending on the calibration and model uncertainty in accuracy is 0.05%. The zero point is an important factor in measuring flow, this affects the uncertainty of flow and the turn down. Rheonik have developed a meter range with a very impressive zero point. The low end of the turn down or low end of a meter’s flow measurement range is mostly affected at the low flow end. To keep the low flow end to a suitable accuracy the zero point must be low. Any deviation from zero point at low flows will give a larger percentage of error. With an impressive 0.000036Kg/min zero point, Rheonik can boast a high turn down and low uncertainty of reading. Accuracy curves are available, by model these plot accuracy versus the flow rate.

Pressure drop

We have covered pressure ratings; the next step of consideration is the pressure drop across any device. The pressure on the inlet will drop across the Rheonik Flow meter, this is mostly due to the velocity of the fluid in the tube size selected for the flow range required. This is particularly important to understand when flowing Gases, Liquids have less of a pressure drop. Pressure drop curves are available, these plot Pressure drop versus Flow Rate: The higher the flow rate the greater the pressure drop.

Materials of construction

Having selected the appropriate model from the fluid type, the Flow, Pressure and Temperature requirements, this dictates the Materials of construction. Rheonik have options to meet the parament and fluid requirements. Materials include: Stainless Steel 316L, SuperDuplex, Alloy C22 and Sandvik HP160, therefore Rheonik cover all fluid types. Seal selection from Metal and various Elastomeric seal types.

Area of use

The location of use may often be Hazardous, this will therefore warrant the Rheonik Meter to be rated in an ATEX class. Rheonik offer Zone II, Zone I and Zone 0 models and of course non Atex Models where not needed.


The final stage of Coriolis selection is what are your conveniences to make the installation simply, allow for measured valves from the Instrument to be best used, whether by display on a transmitter or the data captured to be exported to software for process monitoring and optimisation the date can be sent in various electrical formats.

The Options list is enormous and can depend on many variables, such as:

  • Orientation of Flow
  • Electrical Signals/ pulses you prefer
  • Parameters you want to measure, Flow, Temperature and Fluid Density
  • Certification of Calibration and Certification of Pressure rating
  • Process connections, Threaded or Flanged, size and type… custom made to suit you existing system
  • Seal Materials
  • Transmitter type
  • IP rating


The information provided by the flow meter is used to ensure Standard Operating Procedures are met. Live monitoring of the process is crucial to optimise the product/process. Plotting/monitoring the data can allow the engineer to follow live data to ensure the process is always within it’s required bands of accuracy. Any deviation can be seen live, and adjustments made to rectify before the process and the product is wasted, avoiding unnecessary costs of raw materials, costs of labour, cost of electricity or gas used in the process, delays in delivery and dealing with waste products. Rheonik allows you to ensure the product produced is of high quality, meeting/exceeding the requirements, this giving for optimum yield.

Related article

The Uses of Coriolis Technology with Flow Instruments are Enormous

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Please feel to contact us for expert advice about how coriolis technology can help your process.