TUF (Sure 106) series ultrasonic flow meter is designed on the theory of low voltage and time difference of multi pulse. It can be used to measure transmission time of ultrasound in forward stream and reverse stream, using the methods of high accuracy and super stable double-balanced signal differential transmission and differential receive digital detection technology.
Then calcuate the speed of flow by time difference. It has the trait with high stability, low zero drift and high precision of measurement, wide measuring rang and Strong ability of anti-jaming.
When the ultrasonic wave transmits in the liquid, the flow of the liquid will slightly change the transmitting time of ultrasound wave.

The change of the transmitting time is proportional to the speed of the liquid.
When the speed of the liquid is zero, the time of receiving sound wave of the two sensors is the same(the only way to measure zero speed). When the liquid flows, the transmitting time of sound wave in the forward stream is longer than that in the reverse stream.