Transfer time technical means the ultrasonic signal from the transducer is transmitted and received through the moving liquid. There will be a difference between the upstream and downstream transit time, which can be used to calculate flow and velocity.
Transmit time flow meter sends and receives the ultrasonic waves between transducers in both the upstream and downstream directions in the pipe.
At no flow conditions, it takes the same time to travel upstream and downstream between the transducers. Under flowing conditions, the upstream wave will travel slower and take more time than the downstream wave.
When the fluid moves faster, there is more difference between the upstream and downstream time. The difference in transit times in the upstream and downstream directions measured over the same path can be used to calculate the flow passing through a pipe.
Ft201 is a wall-mount, clamp-on type ultrasonic flow meter which uses the transfer time technology. It is designed using FPGA chip and low-voltage broadband pulse transmission and widely used in HVAC, water treatment, irrigation.
FT201 ultrasonic flow meters of transmit time are more accurate and economical than the Doppler ultrasonic flow meters especially in water.