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What are the factors affecting the accuracy of liquid mass flow meters?

The liquid mass flow meter is a relatively accurate, reliable, efficient, stable and flexible flow measuring instrument. It will be widely used in petroleum processing, chemical industry and other fields, and it also shows great potential in promoting flow measurement.
When using liquid mass flowmeters, what factors will affect the accuracy of the flowmeter? Xiaobian is summarized as follows:
1, installation stress
Treatment method: a. The liquid mass flowmeter should be installed in strict accordance with the installation specifications. b. After the flowmeter is installed, use the hand-held device or the transmitter interface to call up the “zero adjustment menu” and record the factory zero preset value. After the zero adjustment is completed, observe the zero value at this time. The front and back values must be guaranteed. An order of magnitude, if the difference between the two values is large, the installation stress is too large and should be reinstalled.
2, vibration
Treatment: Avoid vibration interference. If it is unavoidable, isolation measures should be taken to isolate the liquid mass flowmeter from the vibration interference source.
3, temperature changes
Treatment method: a. The influence of temperature on the metal elasticity of the flowmeter measuring tube can be solved by setting the temperature correction coefficient; b. The influence of temperature on the zero stability, in practical applications, the mass flowmeter is required under operating temperature conditions. Perform on-site zeroing to minimize impact.
4, pressure changes
Treatment method: For the oil with large change in transmission pressure and trade transfer, pressure transmitter should be installed downstream of the flowmeter to perform pressure compensation in real time in software mode.
5, electromagnetic interference
Treatment method: The liquid mass flowmeter should be installed away from large transformers, motors and other equipment that generate large magnetic fields.
6, the oil contains gas
Treatment method: a. Improve the working condition of the oil, so that the bubbles contained therein are distributed as evenly as possible to meet the requirements of normal metering of the flow meter; b. Install the gas eliminator upstream of the mass flow meter to minimize the phenomenon of gas-liquid mixing; c. Strictly installed according to the mass flowmeter installation specification: measuring the oil medium flow tube installed downwards
7. Oil density and viscosity
Treatment method: Liquid mass flowmeter should be used to measure oil with little difference in density or density. For mass flowmeters used for bulk oil delivery, online flow calibration must be used and equipped with online density meter.
8. Measuring tube damage or corrosion
Treatment method: a. Install the corresponding filter on the front end of the liquid mass flow meter to prevent foreign matter from entering; b. Use a special material flow meter.
In addition, in order for the liquid mass flow meter to work better for us, we recommend that the following conditions should be avoided during the measurement process:
1. The rigid and unstressed support of the sensor;
2. Avoid installing the sensor at the highest position of the pipe, because the bubbles will collect and stay, causing measurement errors in the test system;
3. Additional devices such as regulating valves and inspection observation windows should be installed at least 1X "L" away from the sensor (L is the distance between the sensor mounting flanges);
4. The bracket can not be installed on the flange or the outer casing, and the distance from the flange is generally 20~200mm;
5. If it is not possible to avoid excessively long downstream pipelines (generally not more than 3M), an additional flow valve should be installed;
6. The distance from the pump should be at least 4 times longer than the length of the sensor itself (distance between the two flanges). If the pump causes excessive vibration, it must be isolated by a coiled tube or connecting tube.

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