Coriolis Mass Flow Meter

Coriolis Mass Flow Meter Principle & Overview

The structure of Coriolis Mass Flow Meters was consisted of a pair of bended tubes. The principle is to detect Coriolis force which is forced on a pair of tubes from inner mass flow by fluid.
A new force-Coriolis force would be appearing while two conditions are met:
a. Vibrating with normal frequency in a pair of bended tubes,
b. Fluid flowing in tubes. This force was produced upon synthesis from vibrating force and flowing force by fluid in tubes. And tubes would be wresting symmetric the center line because the force forced. Two displacement sensors on sides of tubes detect the force and output electric signals.
The signals regulated and mass flow directly produced.

Features of Coriolis flow meter

• Coriolis mass Flow meter can take direct measurement of mass flow with high accuracy. It can measure gas,liquid and steam.
• It can even measure liquid containing small amount of gas ,such as it is used as Refrigerant flow meter.
• Various fluids can be measured by Coriolis mass flow sensors, it can be used as asphalt mass flow meter, molasses flow meters，syrup flow meters, glucose flow meter, slurry flow meter,it is a kind high viscosity flow meter.
• Insensitive to fluid flow rate distribution, so have no requirement for the straight pipe requirements
• Mass Flow measurement is not affected by media characteristics
• Multiple parameters such as density measurement, temperature, viscosity, and concentration of solute in solution can be measured by Coriolis meter.
• If you want to buy cheap price coriolis meters and contact the coriolis mass flow meter manufacturers, do not hesitate to contact us

Technical Parameters

• Medium: liquid, gas, solid, or two phases mixed fluid
• Flow Accuracy :±0.2%~±0.1% flow
• Density Accuracy: ±0.002g/cm³,±0.001g/cm³
• Repeatability: ±0.10% ,±0.05%
• Operation Pressure: (0~32) MPa (in case of other high pressure, it must be of special order)
• Medium Temperature :-50°C~ +350°C,
• Environment temperature :-20°C ~ +70°C for transmitters , and -40°C ~ +150°C for sensors
• Output signal:

(1) 4-20mA current signal of flow, with load resistance ≤500Ω
(2) 0-10KHz, frequency signal of instant flow.
(3) RS485 Communication protocol
(4) Hart protocol

• Power supply voltage: 24VDC
• Material of measuring Tube: 316L stainless steel or hastelloy alloy C
• Response time: 0.1s～5s, adjustable
• Explosion-proof grade: EX d ib II C T5 Gb

Model Selection

Here is a video to show to you how our Coriolis flow meter look.

Installation of Coriolis mass flow meter

The proper installation is very important for the performance of the Coriolis Mass Flow Meters. The installation location should be chosen the place that easy for the maintenance. Would you please read the content of the chapter carefully before the installations.

The requirements for the installation:

1. The coriolis mass flow meters are working based on the vibration working principle. So it is the best that there will be no vibration on the installation place. And the strong support of the installation pipelines of the coriolis mass flow meters is very import. If the vibration can not be ignored, it is suggested to use the soft tube connection. And the connections pipelines and the mass flow meters should be on the same axis. Please do not add additional force on the mass flow meters, otherwise the accuracy of the mass flow meters might be affected.

2. If the percentage of the gas in the measured liquids is high, then it is a must to install the gas- liquid separation tank on the inlet of the coriolis mass flow meters.

3. The throttle devices, for example the flow control valves should be installed on the outlet of the mass flow meters.

4. The mass flow meters should be installed away from the outlet of the pumps. Especially for the dual pumps, if the installation distance is too close, then the measured flow rate could be affected, which is fluctuated.

5. If measuring high temperature liquids or it is required to keep warm of the measure medium, please keep distance between the inner tubes of the heating jackets or the heating tubes with the housings of the sensor. We factory also provide the heating jackets along with the mass flow meters, for example the heating jackets for steam or transfer oil. (need to special ordered).

6. The measured liquids should be on the suitable flowing status. If under the local environment the flowing status of the liquids is not suitable, then it is suggested to improve with other methods, for example to modify the temperature of the liquids ( increasing / decreasing the temperature of the liquids to make sure the measured liquids are in the proper flowing status.

7. Installation direction : please make sure the flowing direction should be the same with the direction marks on the nameplates of the coriolis mass flow meters. Otherwise the accuracy of the mass flow meters could be affected.

8. Please make sure the series numbers of the transmitters and the sensors are one -to-one corresponded to each other. It can not be easily changed. Otherwise the accuracy of the mass flow meters could be affected.

9. If the mass flow meters are installed on the outdoors, then it is the best to install the rain shelters for the mass flow meters. And please make sure to keep both the front and back covers of the mass flow meters tightly closed. And please make sure that the electrical interface is sealed well to prevent the waters flowing inside the transmitters.

10. It is suggested to use the normal working flow rate higher than the 1/3 of the standard flow range of the mass flow meters. And it is suggested that the actual minimum flow rate should be higher than the 1/10 of the standard flow range of the mass flow meters. If it is in special situation, please communicate with the sales of our company. As we have our own R&D team, we can customize the mass flow meters based on your own special requirements, to make sure that we can meet with the requirements of the users of the usage range.

II. Installation method for the coriolis mass flow meters: (pipeline size : 10-300mm)

A. Horizontal installation :

► Application : measurement of liquid

► Installation method for the measurement of liquids. The gas that possible stored in the pipelines of the mass flow meters can be easily released and emptied.

B. Inverted installation :

► Application : measurement of gas, or liquids with high viscosity that can be easily stick on the pipelines.

► The liquids that possible stored in the pipelines of the mass flow meters can be easily released and emptied.

C. Flag type installation :

► Application : measurement of liquid with high viscosity, suspension liquid, double phase liquid of both liquid and solid, or some special working situations.

► The liquids with high temperature that easily solidified that possible stored in the pipelines of the mass flow meters can be easily released and emptied. The flag type installation will not affect the accuracy of measurement in any situation. The direction of the flow must be from bottom to up.

Wiring guidance for the transmitters.

SH-CMF Series Coriolis flow meter MODBUS RTU RS485 setting

Check Method: no check 
Data Bits: 8 
Stop Bits: 1 
ModBus Communication Protocol (RTU)
1. Read N variables
The host requested information frame:
Mass Flow Meter Address+Ox03+Register's Starting Address (2bytes, High Byte is in the front) + Number of Register's Reading and Writing 2*N (2bytes, High Byte is in the front) + CRC Check Code (2bytes, Low Byte is in the front)
Response Information from the machine frame: 
Mass Flow Meter Address +Ox03+Bytes of Data 4*N (1字节） ＋Register's Data (4*N bytes, High Byte is in the front) + CRC Check Code (2 bytes, Low Byte is in the front) 
For Example: 
2. Write N variables
The host requested information frame:
Mass Flow Meter Address +Function Code OxlO+ Register's Starting Address (2 bytes, High Byte is in the front)+ Number of Register's Reading and Writing 2*N(2bytes, High Byte is in the front)
+ Bytes of Data 4*N (lbyte) +Data waiting to be written (4*N bytes, High Byte is in the front)
+ CRC Check Code (2 bytes, Low Byte is in the front)
Response Information from the machine frame:
Mass Flow Meter Address + Function Code OxlO+ Register's Starting Address (2 bytes, High Byte is in the front) Number of Register's Reading and Writing 2*N (2bytes, High Byte is in the front)
+
(2 bytes, Low Byte is in the front)