Dwyer's UFM Ultrasonic Flowmeter is a clamp-on unit
Dwyer Instruments' UFM Ultrasonic Flowmeter is a compact, low cost clamp-on, ultrasonic flowmeter. It has a compact and lightweight design, featuring an all in one clamp-on unit. This unit can measure velocity and flow in steel, copper, plastic pipes with outside diameters ranging from 0.98 to 4.62” (24.89 to 117.35 mm). This series comes with a volume pulsed output and 4 to 20 mA flow rate output. This model is capable of displaying instantaneous and totalized flow for monitoring flow and batch quantity.
The model UFM operates via the transit-time difference with two sensors located in the guiderail that is placed on the exterior of the pipe, and each sensor transmits an ultrasonic pulse through the pipe and fluid to the other. The velocity of the liquid flowing through the pipes causes the pulse to accelerate or decelerate. The difference in the transit times of the two pulses is used to calculate the flow rate. The use of transit time allows the flowmeter to be unaffected by pressure or temperature changes.