Q, when there are bubbles in the pipeline, is the ultrasonic flowmeter measurement accurate?
A: When there are bubbles in the pipeline, if the bubbles affect the decline of the signal, it will affect the accuracy of the measurement.
Solution: First remove the bubble and then measure.
Q: Ultrasonic flowmeter can not be used in the field of strong interference?
A: The fluctuation range of the power supply is large, there is a frequency converter or strong magnetic field interference around, and the ground line is incorrect.
Solution: To provide a stable power supply for the ultrasonic flowmeter, the flowmeter installation away from the frequency converter and strong magnetic field interference, there is a good grounding line.
Q: Ultrasonic plug-in sensors after a period of time after the signal is reduced?
A: The ultrasonic plug-in sensor may be offset or the sensor surface scale is thick.
Solution: readjust the position of the ultrasonic inserted sensor and clear the transmitting surface of the sensor.
Q: Ultrasonic outside clamp flowmeter signal is low?
Answer: The pipe diameter is too large, the pipe scale is serious, or the installation method is not correct.
Solution: For the pipe diameter is too large, serious scaling, it is recommended to use ultrasonic inserted sensor, or choose “Z” type installation.
Q: Is the instantaneous flow fluctuation of ultrasonic flowmeter large?
A. The signal strength fluctuates greatly; B, the measurement fluid fluctuation;
Solution: Adjust the position of the ultrasonic sensor, improve the signal strength, and ensure the stability of the signal strength. If the fluid fluctuation is large, the position is not good, and re-select the point to ensure the working condition requirements of 5D after *D.
Q: Ultrasonic flowmeter measurement time transmission ratio of less than 100%±3, what is the reason, how to improve?
A: Improper installation, or incorrect pipeline parameters, to detect whether the pipeline parameters are accurate, installation distance is correct
Q: Ultrasonic flowmeter can not detect the signal?
A: Confirm whether the pipeline parameters are correctly set, whether the installation method is correct, whether the connection line is in good contact, whether the pipeline is filled with fluid, whether the measured medium contains bubbles, whether the ultrasonic sensor is installed according to the installation distance displayed by the ultrasonic flowmeter host, and whether the sensor installation direction is wrong.
Q: Ultrasonic flowmeter Q value reaches below 60, what is the cause? How to improve?
A: If there is no problem with the installation in the field, the low Q value may be caused by the fluid in the pipeline under test, the presence of bubbles, or the presence of frequency conversion and high pressure equipment in the surrounding working conditions.
1) Ensure that the fluid in the pipeline under test is full and there is no bubble (install the exhaust valve);
2) Ensure that the measuring host and ultrasonic sensor are well grounded;
3) The working power supply of ultrasonic flowmeter should not share a power supply with frequency conversion and high voltage equipment, and try to use DC power supply to work;
4) The ultrasonic sensor signal line should not be parallel with the power cable, and should be parallel with the flow meter signal cable or a separate line and a metal tube to protect the shield;
5) Keep the ultrasonic flowmeter machine away from the interference environment;
Q, ultrasonic flowmeter cable laying precautions?
1. When laying the ultrasonic flowmeter cable tube, try to lay the power cord and signal line separately, do not use the same pipe, choose 4 points (1/2 “) or 6 points (3/4 “) galvanized pipe, which can be parallel.
2, when laying underground, it is recommended that the cable wear a metal tube to prevent the cable from being rolled or bitten by rats, the outer diameter of the cable is 9 mm, each pair of ultrasonic sensor 2 cables, the inner diameter of the metal tube should be greater than 30 mm.
3, to be isolated from the power line, and other cables laying the same cable trench, need to wear metal pipes to improve anti-interference performance.
External clamped ultrasonic flowmeter is a kind of flow meter very suitable for full pipe measurement, with easy installation and non-contact, both can measure the medium flow of large pipe diameter can also be used for measuring the medium that is not easy to contact and observe, its measurement accuracy is very high, almost free from the interference of various parameters of the measured medium. In particular, it can solve the flow measurement problems of highly corrosive, non-conductive, radioactive and flammable and explosive media that other instruments cannot. Because it has the above other types of instruments do not have the characteristics, has been widely used in the industrial various tap water, sewage, sea water and other liquid measurement, but also used in petroleum, chemical, metallurgy and other fields.
The external clamp-type ultrasonic flowmeter can generally operate normally for a long time after installation without maintenance, and it is not necessary to be surprised if the problem of receiving no signal or too weak signal occurs, as long as you have to recommend five steps according to Xiyuan instrument technology, standardized operation and careful treatment will quickly return to normal:
1. First confirm whether the flowmeter in the pipeline is full of fluid;
2. If the pipe is too close to the wall, the probe can be installed on the diameter of the pipe with a inclined Angle, rather than on the diameter of the horizontal pipe, the Z method should be used to install the probe;
3. Carefully select the dense part of the pipeline and fully polish it, apply sufficient lotus root mixture to install the probe;
4. Carefully move each probe slowly near the installation point to find a larger signal point to prevent the installation point that can receive a stronger signal from being missed due to scaling on the inner wall of the pipeline or due to local deformation of the pipeline that causes the ultrasonic beam to reflect the expected area;
5. For metal pipes with serious scaling on the inner wall, the method of striking can be used to make the scaling part fall off or crack, but it should be noted that this method sometimes does not help the transmission of ultrasonic waves because of the gap between the scaling and the inner wall.
Because the external clamped ultrasonic flowmeter is commonly used to measure dirty fluid, after running for a period of time, it often accumulates adhesive layer on the inner wall of the sensor and causes failure. It is recommended that the filter device can be installed in the upstream if there are conditions, which will better play the stability of the instrument and maintain the stability of the measurement data.
Post time: Sep-04-2023