TrueFlow Technology - How it works
The TrueFlow sensor
Ultrasonic pulse transit-time measurement
What is transit-time measurement?
A simple and proven method to measure how long it takes for a signal to travel from one point to another.
The contactless flow sensor
respiratory diagnostics.
How it works - Flow measurement operating principle
1.
Two ultrasonic transducers are located diagonally across a gas flow path.
2.
As soon as air passes through, a pulse of ultrasound is emitted by one transducer, travels diagonally with the gas flow and is received by the opposite transducer.
3.
In the meantime, a second pulse of ultrasound is emitted by the opposite transducer which travels diagonally against the gas flow and is received by the opposite transducer.
4.
If there is no air flow through the flow path, then the upstream and downstream transit-times are identical.
5.
As air flows from left to right, the upstream pulse travels faster.
6.
The downstream pulse, however, travels slower. Therefore, a gas flow results in a difference in the up and downstream transit-times.