The operating principle of ultrasonic flowmeters is based on the mathematical relationship between transit time and flow rate, which assumes a fully developed velocity distribution in the pipe. Our transit-time ultrasonic flowmeters use a single line across the cross section to represent the surface. Furthermore, the meter factor of ultrasonic flowmeters is determined at the factory using fully developed flow conditions on test equipment. Therefore, if the fluid does not meet fully developed flow conditions during actual measurement, the established flow relationship will not be met, and the factory-determined meter factor will not be reproduced, resulting in significant measurement errors. Fully developed flow can only be achieved with sufficient straight pipe length. Therefore, to ensure fully developed flow conditions, additional straight pipe sections must be added before and after the flowmeter to ensure measurement accuracy. Insufficient straight pipe length can create various interfering flow conditions, leading to non-axisymmetric flow and complex measurement effects. Clamp-on flowmeters are more susceptible to installation problems, which often result in lower-than-normal flow rates.
