Ultrasonic flow meter use precautions
Ultrasonic flow meter is a speed flow meter that uses ultrasonic pulse to measure fluid flow. It adopts advanced multi- pulse technology, signal digitization processing technology and error correction technology, which makes the flow meter more adaptable to the industrial scene environment, and the measurement is more convenient, economic and accurate. It can be widely used in petroleum, chemical, metallurgy, electric power and other fields. At present, ultrasonic flow meters are getting more and more attention from various enterprises. In the process of using ultrasonic flow meters, what we should pay attention to is as follows:
1. Correct selection
Proper selection is the basis for ensuring the proper operation of the ultrasonic flow meter. If the selection is not correct, the flow will not be measured, or the user may not use it.
2. Reasonable installation
Unreasonable installation of the transducer is the main reason why the ultrasonic flow meter does not work properly. The determination of the location and the choice of mode are the first two issues to consider when installing the transducer. When determining the installation position, in addition to ensuring sufficient upstream and downstream straight pipe sections, it is also necessary to pay attention to the occasion where the transducer avoids contaminated power sources such as inverters and electric welders. There are three types of installation methods: the mounting method, the V mode and the Z mode. The Doppler ultrasonic flow meter adopts a pair-mounted installation method, and the time difference type ultrasonic wave adopts a V mode and a Z mode. Normally, when the pipe diameter is less than 200mm, it is installed by V mode. When the pipe diameter is larger than 200mm, it is installed by Z mode. If you use the V mode and the Z mode, you can use the Z mode. Practice has shown that the Z-mode installed transducer ultrasonic flow meter has good signal strength and good measurement stability.
3. Timely nuclear school
If the number of fixed ultrasonic flow meters installed on site is large, a wide range of users can be equipped with a portable ultrasonic flow meter of the same type for use in nuclear field instruments. The first is to insist on one school and one school, that is, to check each new ultrasonic flow meter during installation and debugging, to ensure that the selection is good, the installation is good, and the measurement is accurate; the second is that when the ultrasonic flow meter is in abrupt change, Use the portable ultrasonic flow meter to perform timely nuclear calibration, find out the cause of sudden changes in flow, and clarify the faults that occur in the instrument.
4. Regular maintenance
Ultrasonic flow meter maintenance is relatively small compared to other flow meters. For the externally attached transducer ultrasonic flow meter, the water pressure would be in a loss after installation, then no water leakage phenomenon, only need to periodically check whether the transducer is loose, or whether the adhesive between the pipeline is good. The plug-in ultrasonic flow meter, regularly to clean the impurities, scale, and water leakage on the probe. If it is an integrated ultrasonic flow meter, to check the flange link between the flow meter and the pipe, and consider the temperature and humidity of the site.
(1) No signal
First, you need to disconnect and relink the transducer and the host. The second is to check whether the pipeline has water or whether the installation location is reasonable.
(2) Insufficient signal strength
Check the appearance of power pollution, clean the power supply. Secondly, check the transducer position to move, and re- adjust the transducer position.
(3) The instantaneous flow rate is stable, but the actual value is too large.
The transducer wedge has failed and the transducer has been replaced.
(4) Large instantaneous flow fluctuations
Firstly, the fluid is disturbed, unstable, and the transducer position needs to be replaced. Second, the host rental coefficient is set too small, and the negative coefficient is required to be adjusted.
(5) Instantaneous and cumulative flow inconsistency
Check that the host is faulty and you need to replace the host.