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Coriolis flowmeters are among the most accurate instruments for directly measuring mass flow. Based on the Coriolis effect, these devices can simultaneously measure additional parameters such as fluid density, temperature, and viscosity. Due to their unmatched accuracy, they are widely used in chemical, petrochemical, food, pharmaceutical, energy, and oil & gas industries.

WORKING PRINCIPLE

Coriolis flowmeters measure mass flow by detecting the phase shift caused when fluid passes through vibrating tubes. The tubes are set into oscillation by electromagnetic drivers. As the fluid flows, a measurable phase difference appears between the inlet and outlet ends of the tube, which is proportional to the mass flow.

Basic equation:
ṁ = k · Δφ
ṁ: mass flow rate (kg/s), k: calibration constant, Δφ: phase shift (radians).

Additionally, the natural vibration frequency of the tubes is used to measure fluid density:
ρ = f(ω)
ρ: density, ω: vibration frequency.

STRUCTURAL FEATURES

Measuring tubes: U-shaped or dual straight tube designs
Materials: Stainless steel, Hastelloy, or corrosion-resistant alloys
Sensors: Electromagnetic or optical detection
Output: 4-20 mA, HART, Profibus, Modbus, Foundation Fieldbus
Additional functions: Density, temperature, and viscosity measurement

ADVANTAGES AND LIMITATIONS

Advantages:

Direct mass flow measurement
Very high accuracy (±0.1% – ±0.2%)
Simultaneous density and temperature measurement
No moving parts, minimal maintenance

Limitations:

High initial cost
Heavy and expensive for large pipe diameters
Sensitive to vibrations and installation conditions

APPLICATION AREAS

Chemical and petrochemical industry: measurement of acids, bases, and solutions
Oil and gas industry: mass flow measurement
Food and beverage production: sugar solutions, milk, beer, etc.
Pharmaceutical industry: precise formulations
Energy sector: fuel feed and process control

STANDARDS AND CALIBRATION

ISO 10790: International standard for Coriolis flowmeters
OIML R 137: International standard for gas flow measurement devices
ATEX-certified versions: For explosive environments
Regular calibration is essential to maintain accuracy

CONCLUSION

Coriolis flowmeters provide unmatched accuracy and versatility by offering direct mass flow measurement combined with density and temperature monitoring. They are indispensable instruments in modern process industries, particularly where precision and reliability are critical.

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