Flow Meters › Coriolis Flow Meters › Coriolis Mass Flow Meter
Coriolis Mass Flow Meter
A flow meter that measures mass directly from the Coriolis force on a vibrating tube, not inferred from volume. It reads mass flow, density, and temperature in one instrument, holds 0.1% to 0.5% accuracy, and needs no straight pipe run. Sizes from DN3 to DN200, for liquids, slurries, and gases.
- Principle: Coriolis, vibrating tube; direct mass and density
- Size: DN3 to DN200
- Accuracy: 0.1% to 0.5% of rate; density ±0.002 g/cm³
- Output: 4-20 mA, pulse, RS-485 Modbus; HART option
- Rating: IP67; Ex d [ia] IIC T6 Gb
Overview
A Coriolis mass flow meter measures mass flow directly. The fluid passes through a vibrating tube, and the Coriolis force the moving mass exerts on the tube twists it; the phase shift between the two ends of the tube is proportional to the mass flow rate. Because the reading comes from mass and not from volume, it does not drift with changes in pressure, temperature, or density, and the same instrument reports the fluid density and temperature at the same time.
The meter is built as a stainless steel sensor and a signal converter, in sizes from DN3 to DN200. The measuring tube is 316L and the housing is 304. It holds an accuracy of 0.1% to 0.5% of rate, measures density to ±0.002 g/cm³, and needs no upstream or downstream straight pipe run. It suits clean liquids, high-viscosity fluids, slurries and suspensions, and medium-to-high-pressure gas. For density measurement on its own, see the Coriolis density meter.
Features
Everything here follows from one fact: the meter weighs the flow instead of timing or counting it.
Direct mass measurement
It reads mass flow from the Coriolis force, so the result does not shift with pressure, temperature, or density.
0.1% to 0.5% accuracy
Class 0.1, 0.15, 0.2, and 0.5 are available, with a measurable ratio of 10:1 to 20:1.
Mass, density, temperature
One instrument outputs mass flow, working density to ±0.002 g/cm³, and medium temperature.
Hard fluids and slurries
It measures high-viscosity fluids, grouts, and suspensions that other meters struggle with.
No straight run, no moving parts
It needs no upstream or downstream straight pipe, and there is nothing inside the line to wear.
4-20 mA, pulse, RS-485, HART
An LED or LCD converter drives analog, pulse, and Modbus outputs, with HART on the LCD models.
Working principle
The sensor holds one or two measuring tubes that a drive coil vibrates at their natural frequency. With no flow, both halves of the tube vibrate in step. When fluid flows, each moving mass element resists the change in its direction of motion, and that reaction is the Coriolis force. It acts in opposite directions on the inlet and outlet halves of the tube, so the tube twists, and the two halves move out of step. Position detectors at each end measure this phase, or time, difference. The phase difference is directly proportional to the mass flow rate, while the natural frequency of the tube shifts with the fluid density, so the meter derives both from the same vibrating tube. Sensors from DN20 to DN200 use a U-tube structure; DN3 to DN15 use a compact triangular structure.
Technical specifications
| Parameter | Specification |
|---|---|
| Measurement principle | Coriolis, vibrating tube; direct mass flow, density, temperature |
| Sensor structure | U-tube (DN20 to DN200); triangular (DN3 to DN15) |
| Size | DN3 to DN200 |
| Accuracy (mass, liquid) | Class 0.1, 0.15, 0.2, 0.5 (% of rate) |
| Turndown | 10:1 to 20:1 |
| Density measurement | 0.3 to 3.000 g/cm³, accuracy ±0.002 g/cm³ |
| Temperature measurement | -200 to 350 C, accuracy ±1 C |
| Medium temperature | Standard -50 to 200 C; high-temp -50 to 350 C; low-temp -200 to 200 C |
| Ambient temperature | -40 to 60 C (LED), -20 to 60 C (LCD) |
| Working pressure | 0 to 4.0 MPa standard; to 30 MPa on request |
| Wetted material | Measuring tube 316L; housing 304 |
| Connection | Flange, sanitary clamp, or thread (DIN, ANSI, JIS, GB, HG) |
| Outputs | 4-20 mA (load ≥750 ohm) and 0 to 10 kHz pulse; pulse 0.05%, current 0.2% |
| Communication | RS-485 Modbus; HART on LCD models |
| Display | Two-row LED or three-row LCD; mass, volume, density, temperature, totalizer |
| Power | 18 to 36 VDC or 85 to 265 VAC; 7 to 10 W |
| Mounting | Integral or split (2 m signal cable) |
| Protection | IP67 |
| Explosion protection | Ex d [ia] IIC T6 Gb |
Representative specifications; confirm per datasheet for the size, pressure, and material you need.
Ordering example. DN15 Coriolis mass flow meter, class 0.2, 316L tube, flange connection, split converter with 4-20 mA, pulse, and RS-485.
Flow ranges by size
The standard flow range is the value recommended for factory calibration and normal operation; the upper-limit range is the maximum for stable sensor operation. Working in the middle third of the standard range gives the best accuracy and the lowest pressure loss.
| Size | Standard flow (kg/h) | Upper limit (kg/h) |
|---|---|---|
| DN3 | 96 | 144 |
| DN6 | 540 | 810 |
| DN8 | 960 | 1440 |
| DN10 | 1500 | 2250 |
| DN15 | 3000 | 4500 |
| DN20 | 6000 | 9000 |
| DN25 | 9600 | 14400 |
| DN32 | 18000 | 27000 |
| DN40 | 30000 | 45000 |
| DN50 | 48000 | 72000 |
| DN80 | 120000 | 180000 |
| DN100 | 192000 | 300000 |
| DN150 | 360000 | on request |
Versions
The sensor and converter are configured to the fluid and the duty point:
- Standard. 316L tube, medium -50 to 200 C, working pressure to 4.0 MPa. The default for most liquids and gases.
- High-temperature. Medium to 350 C, for hot oil and other high-temperature service.
- Low-temperature. Medium to -200 C, for liquid nitrogen, liquid oxygen, and other liquefied gas.
- High-pressure. Working pressure to 30 MPa, for cementing and other high-pressure service.
- Insulation (heat-preserving). A jacketed sensor circulates steam or hot oil to keep media such as asphalt above their solidifying point.
The converter is integral with the sensor, or split with a 2 m cable where the medium is hot or the sensor is hard to read at.
Applications
Direct mass measurement makes the meter the reference for custody and for hard fluids:
- Custody transfer of petroleum and chemical loading and unloading
- Mass dosing and batching in chemical, food, and pharmaceutical lines
- High-viscosity fluids: asphalt, heavy oil, resin
- Slurries and suspensions: cement slurry, lime slurry
- Medium-to-high-pressure gas, including CNG and natural gas
- Small-flow dosing in fine chemical and pharmaceutical production
- Cryogenic liquids such as liquid nitrogen and liquid oxygen
Application example
Fine-chemical micro-dosing. A specialty-chemical producer needed to dose a polyaluminium-chloride stream at about 15 mL/min on a small line, where the flow is too low and the fluid too variable for a volume meter to hold its accuracy. A small-bore Coriolis sensor measured the dose by mass directly, independent of the changing density, and reported the rate and the running total to the dosing controller. Measuring mass rather than volume held the dose steady as the fluid varied.
Related products
Coriolis Density MeterThe same vibrating tube, for density measurement.
Large Diameter Coriolis Flow MeterBig-bore U-tube, DN80 to DN200, up to about 1,200 t/h for loading and custody transfer.
Straight Tube Coriolis Flow MeterSingle straight tube: self-draining, low pressure drop, for CIP, slurry, and sticky media.
Turbine Flow MeterVolumetric measurement for clean, low-viscosity liquids.
Browse all Coriolis flow meters →
Related applications: Natural gas, Chemical, Diesel, High viscosity.
FAQ
How does a Coriolis flow meter work?
Fluid flows through a tube that is vibrated at its natural frequency. The Coriolis force from the moving mass twists the tube, and the phase difference between the two ends is proportional to the mass flow rate. The natural frequency shifts with the fluid density, so the meter reports mass flow, density, and temperature together.
How accurate is a Coriolis mass flow meter?
This meter is available in class 0.1, 0.15, 0.2, and 0.5, that is 0.1% to 0.5% of rate, with density to ±0.002 g/cm³. Because it measures mass directly, the reading does not drift with pressure, temperature, or density.
What is the difference between mass and volume flow?
A volume meter measures how much space the fluid takes up, which changes with temperature and pressure. A Coriolis meter measures mass, the actual amount of material, so it does not need separate pressure, temperature, or density correction. That is why it is the usual choice for custody transfer and batching.
Does it need straight pipe runs?
No. Unlike most flow meters, a Coriolis meter does not require upstream or downstream straight pipe. It does need solid pipe support and the correct tube orientation, vertical for self-draining liquid service and avoiding horizontal mounting of the vibrating tube.
Can it measure gas and slurry?
Yes. It measures medium-to-high-pressure gas such as CNG, and high-viscosity fluids, grouts, and suspensions. It is not suited to fluids carrying entrained gas bubbles, which disturb the vibrating tube.
Request a quote
Send us the fluid, the flow range, the line size, and the temperature and pressure, and we size the sensor and set the converter outputs. Standard, high-temperature, low-temperature, high-pressure, and insulated builds are available.