How does the Transit-Time Ultrasound Method work?
em-tec offers many different flow measurement systems which are based on the transit-time ultrasound principle:
The SonoTT Vascular Probe surrounds the blood vessel, generating an ultrasound field across the whole vessel diameter. Ultrasonic impulses are sent from one piezo crystal to another via the reflector, with the crystals acting alternately as transmitters and receivers. The transit time taken by each impulse is determined. The differences in transit times taken by the impulses flowing up-stream and the ones flowing downstream are proportional to the flow rate. The measurement principle of em-tec’s Clamp-on Transducers for tubing systems is also based on the transit-time method. Four piezo crystals arranged in an X configuration scan the fluid flow by ultrasonic transmission, calculating the differences of upstream and downstream transit times.