Where are the advantages and disadvantages of clamp-on ultrasonic flowmeters?

With the rapid progress of ultrasonic sensor technology, its application in various fields of production and life is becoming wider and wider. Time-difference ultrasonic flowmeters and Doppler ultrasonic flowmeters in industrial production are very popular, and the market sales of products are growing exponentially. It has also been widely used in the fields of medical care, transportation, water supply, etc. that are closely related to residents' lives. For example, B-ultrasound and color ultrasound commonly mentioned in medical treatment, speedometers at traffic stations, and water volume measurement in tap water pipes can all see the presence of ultrasonic sensor technology. It is precisely because of the great advantages of ultrasonic flow sensor technology that it is liked by users, and with the deepening of related research and development technologies, ultrasonic sensor technology will be more closely related to people's production and life.

This article describes the use of ultrasonic sensor technology in industrial flow measurement and lists the advantages of ultrasonic flowmeters over other types of flowmeters. It also explains how the ultrasonic flowmeter will be affected by certain specific situations. Specifically, the advantages of the time difference clamp-on ultrasonic flowmeter include the following aspects:

1. The clamp-on ultrasonic flowmeter is a non-contact measurement method. The sensor used for measurement does not need to be in direct contact with the measured liquid. The measurement structure is not affected by the viscosity and conductivity of the measured fluid, so it can measure the flow of various liquids or gases. It can be used for the flow measurement of various liquids or gases. It can be used for measuring the flow of various liquids, including measuring the flow of turbid liquids, high-viscosity liquids and non-conductive liquids. It is especially suitable for measuring the water flow of large-diameter pipelines or the flow rate and flow of various canals, rivers, and seawater. It is also used in medicine to measure blood flow, etc.

2. Particularly suitable for large-diameter measurement. The ultrasonic flowmeter has no obstruction components inserted into the pipeline, and only relies on the conduction and reflection of sound waves to achieve the measurement purpose. The clamp-on ultrasonic flowmeter can measure diameters of more than 10m, which can solve the large-diameter measurement problem that other flowmeters cannot solve at present, and its cost and quality are basically independent of the diameter of the measured pipeline.

3. It can measure liquid media containing a large amount of impurities and bubbles, and can solve problems in industries such as sewage treatment and environmental protection that cannot be measured using other flow meters.

4. Energy saving: Ultrasonic flowmeters do not need to be inserted into the measured flow field, have no pressure loss, and consume very little energy. They are an ideal energy-saving instrument. Especially for the measurement of large flows, the energy-saving benefits are more significant.

5. Because the ultrasonic flowmeter does not work based on the electromagnetic principle, it is not related to the conductivity of the liquid medium. It is perfectly capable of measuring the flow of non-conductive liquid media. This non-contact measurement method is a good supplement to the electromagnetic flowmeter.

6. Does not interfere with the flow field. This is a supplement to contact flow meters for those occasions where disturbance of the flow field is not allowed.

7. It can measure highly corrosive, explosive and radioactive media; the measurement is not affected by medium pressure, temperature, viscosity, density, etc.

8. The detection parts are easy to repair and replace without interrupting the flow (except for built-in types).

9. The flow rate and output signal are linearly related, which is suitable for wide range of flow measurement.

10. The transducer has a simple structure, no moving parts, long service life and light weight.

11. High sensitivity and time resolution. Some products have a sensitivity of up to 0.0003m/s and a time resolution of up to 0.001ns.

12. It is not only suitable for large-caliber measurement, but also for small-caliber measurement.
 

Based on the constraints of current ultrasonic sensor technology and current production processes, ultrasonic flow meters still have the following weaknesses. These weaknesses will be improved and overcome to varying degrees with the advancement of related technologies. The current weaknesses of ultrasonic flow meters include the following:　　

(1) The main disadvantages of ultrasonic flowmeters are that the temperature range of the measurable fluid is limited by the temperature resistance of the ultrasonic transducer and the coupling material between the transducer and the pipeline, and the original data of the sound transmission velocity of the measured fluid at high temperature is incomplete. At present, it can only be used to measure fluids below 200°C in my country.　　

(2) The anti-interference ability is not ideal, and it is easily affected by bubbles, scaling, pumps, and other ultrasonic noises, resulting in poor accuracy. If the above situation occurs, the accuracy will deteriorate at best, and the instrument will not display at worst.
　    (3) In addition, the measurement circuit of the ultrasonic flowmeter is more complicated than that of the general flowmeter. This is because the flow rate of the liquid in general industrial measurement is often several meters per second, while the propagation speed of sound waves in the liquid is about 1500m/s. The maximum change in the sound velocity caused by the change in the flow rate (flow) of the measured fluid is also on the order of 10-3. If the accuracy of the measured flow rate is required to be ±1%, the measurement accuracy of the sound velocity must be on the order of 10-5 to 10-6, so a perfect measurement circuit must be available to achieve this. This is also the reason why ultrasonic flowmeters can only be put into practical use under the premise of rapid development of integrated circuit technology.

(4) The installation method also has a great impact on the measurement effect of the ultrasonic flowmeter. Incorrect installation methods will affect the measurement accuracy.
With the development of industry and the gradual maturity of the market, the application of ultrasonic flowmeters will become more and more extensive. Whether in industrial production sites or in storage and transfer and financial accounting applications, its application is more comprehensive and extensive. Its superior performance has been recognized by all parties. With the full development of the market, the market adjustment of its price will become more reasonable.