The Series UFB & UFC Ultrasonic Flowmeter Sets utilize the transit time difference for measuring flow rates in pipes non-invasively. Two sensors are placed on the exterior of the pipe, and each transmits an ultrasonic pulse through the pipe and fluid to the other. The difference in the transit times of the two pulses is used to calculate the flow velocity. This is the permanent model, allowing the user to mount the converter on a surface or pipe and easily clamp on the sensors and guide bar. The easy-to-use compact and lightweight design is intended for mechanical devices using ideally homogeneous liquids that contain no air pockets.