Fixed Ultrasonic Flow Meters|Transit Time

 

 

Dynasonics clamp-on ultrasonic flow meters operates using two transducers which function as both ultrasonic transmitters and receivers. The Sensor fucntion by alternately transmitting and receiving a frequency modulated burst of sound energy between the devices two transducers. The first burst us transmitted in the direction of fluid flow, followed by a burst against fluid flow.

 

The sound energy in a moving liquid is carried faster when it travels in the direction of fluid flow (downstream) than it does when the sound travels against fluid flow (upstream), a differential in these times of flight will then occur.

 

This upstream and donstream time of flight is accurately measured and the difference in time of flight calculated. The liquid velocity (V) found inside the pipe can be related to the difference in time of flight (dt) through the following equation: V = K * D * dt, where K is a constant and D is the distance between the transducers