1. Advantages
The clamp-on ultrasonic flow meter is a non-contact instrument that can measure the flow rate of media in large-diameter pipes as well as media that are difficult to access and observe. It boasts high measurement accuracy, virtually unaffected by the various parameters of the measured medium, and is particularly effective in measuring the flow rate of highly corrosive, non-conductive, radioactive, and flammable/explosive media, which are beyond the capabilities of other instruments.
2. Disadvantages
The main drawbacks of current ultrasonic flowmeters are the limitation on the temperature range of the measurable fluid, which is restricted by the temperature resistance of the ultrasonic transducer aluminum and the coupling material between the transducer and the pipe, as well as the incomplete raw data on the sound velocity of the measured fluid at high temperatures. Currently, in my country, they can only be used to measure fluids below 200℃. Furthermore, the measurement circuitry of ultrasonic flowmeters is more complex than that of conventional flowmeters. This is because the flow velocity of liquids in general industrial metering is often a few meters per second, while the speed of sound in liquids is approximately 1500 m/s. The change in sound velocity caused by a change in the flow velocity (flow rate) of the measured fluid is at most on the order of 10⁻³. If a 1% accuracy in measuring flow velocity is required, the accuracy in measuring sound velocity needs to be on the order of 10⁻⁵ to 10⁻⁶. Therefore, a sophisticated measurement circuitry is necessary to achieve this, which is why ultrasonic flowmeters can only be practically applied with the rapid development of integrated circuit technology.
