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Quick Answer: A Coriolis mass flow meter measures true mass flow directly in kg/h. The meter vibrates the flow tube and detects an inertial twist caused by Coriolis force. The phase shift between two sensor points is proportional to mass flow, so the meter does not need pressure and temperature compensation for mass units.
This article is for engineers and buyers in Southeast Asia, Oceania, Latin America, Africa, and the Middle East. Silver Automation Instruments supplies Coriolis mass flow meters for oil and gas, chemical, food and beverage, water and wastewater, and marine service. The working principle below explains the mechanism in practical field terms.
Inside a Coriolis meter one or two flow tubes vibrate at a known frequency from a drive coil. When process fluid enters the tube it moves forward and also moves with the tube vibration. The combined motion creates a Coriolis force inside the tube.
On the inlet side the fluid resists the tube motion. On the outlet side the fluid pushes in the opposite direction. The result is a small inertial twist of the tube. Two electromagnetic sensors measure tube position at the inlet and outlet sections.
With zero flow both sensors see the same phase. With flow the tube twists and the two signals shift apart. That phase shift or time delay is the direct mass flow signal. This is the essence of the Coriolis mass flow meter working principle.
The transmitter receives the sensor signals and calculates mass flow from the time difference. Because the tube also vibrates at its natural frequency the transmitter can calculate fluid density from the frequency change. A built in PT100 sensor tracks tube temperature.
In a chemical batch process in Thailand the output may be 0 to 500 kg/h through a DN15 meter. The transmitter sends a 4-20 mA HART signal and a pulse output for total flow. Operators can read mass flow in kg/h, density in kg/m3, and temperature in °C from one device.
In practice most engineers skip the full math. The meter computes in real time. You receive mass flow, density, temperature, and derived volume flow from a single instrument.
Volumetric flow meters need compensation when pressure and temperature change fluid density. A Coriolis meter does not. For liquid ammonia loading or fuel oil batching the mass reading is the value you control or invoice.
We have seen this on customer sites many times. A food additives plant in Vietnam measured syrup with an oval gear meter and had trouble when density shifted between batches. After changing to a Coriolis meter the batch weight became stable at 1200 kg per run.
A Coriolis mass flow meter does not need long straight pipe runs like a vortex or electromagnetic flow meter. That saves space in skids and offshore platforms. Mount the meter so the tubes remain full of liquid. For gas service follow the supplier drain and purge instructions.
Entrained gas in liquid batching creates measurement noise. A degassing step upstream solves most cases. In high vibration areas use the standard mounting supports from the supplier.
When you send an inquiry include pipe size such as DN15 or DN50, fluid type, flow range, operating pressure in bar, temperature in °C, viscosity in cP, and required accuracy. Also specify wetted materials such as 316L stainless steel or Hastelloy C22. For hazardous areas ask for ATEX Zone 1 or IECEx certification.
A typical specification from a desalination plant in Saudi Arabia is DN25, seawater at 35 °C, flow range 0 to 3000 kg/h, pressure 10 bar, 316L wetted parts, and 4-20 mA HART output. Silver Instruments technical team can confirm the correct model from this data.
Send us your pressure in bar, temperature in °C, pipe size in DN, and flow range in kg/h. You can reach Silver Automation Instruments by phone at +86-25-68650347, WhatsApp at +86-25-52155837, or WeChat at +86 15365082610. For product details see the Coriolis mass flow meter page on flow-meter.com.au.
What is the difference between mass flow and volume flow? Mass flow is expressed in kg/h or t/h. Volume flow is expressed in m3/h or L/h. The Coriolis meter measures mass flow directly and calculates volume flow from density.
Can a Coriolis meter measure gas and liquid? Yes. One meter can handle clean gas or liquid. You need to define the fluid phase and density range when ordering because the sizing changes.
Does high viscosity affect the Coriolis principle? Viscosity does not affect mass flow accuracy in most cases. The meter measures the tube twist directly. This is a major reason why Coriolis meters work for heavy oil, syrup, and polymers.
What materials are available for corrosive fluids? Common wetted parts are 316L stainless steel and Hastelloy C22. For acids and seawater desalination service confirm chloride levels with the supplier before final selection.
What should I send for a fast quote? Send fluid name, flow range, pipe size DN, pressure bar, temperature °C, and hazardous area requirement. A complete inquiry allows Silver Automation Instruments to return a specific offer and delivery date.
