Ultrasonic flow meters can perform non-contact measurements. Clamp-on transducer ultrasonic flow meters do not require pipe closure for installation; the transducer can be installed externally on the existing pipeline. This is a unique advantage of ultrasonic flow meters in industrial flow instruments, enabling mobile (i.e., non-fixed installation) measurements, suitable for assessing and determining flow conditions in pipe networks.
Ultrasonic flow meters provide unobstructed flow measurement with no additional pressure loss.
Ultrasonic flow meters are suitable for large circular and rectangular pipes and are theoretically not limited by pipe diameter, making them a preferred option when actual flow verification is not feasible.
Ultrasonic flow meters can measure non-conductive liquids, complementing electromagnetic flow meters in unobstructed flow measurement.
Some time-of-propagation ultrasonic flow meters have the function of measuring the sound wave propagation time, allowing measurement of the liquid's sound velocity to determine the type of liquid being measured. For example, when pumping oil from an oil tanker ashore, it can be used to verify whether the measured liquid is oil or bottom water.
Time-of-propagation ultrasonic flow meters can only be used for clean liquids and gases.
Ultrasonic flow meters with externally mounted transducers cannot be used in pipes with excessively thick linings or scale, nor in pipes where the lining (or rust layer) has peeled off from the inner pipe wall (if the interlayer contains gas, it will severely attenuate the ultrasonic signal) or where there is severe corrosion (which changes the ultrasonic propagation path).
