How Surface Acoustic Wave flow sensors work
Flow measurement devices all have one or more limiting factors and employ moving parts that are in contact with the fluid, which can cause flow restrictions and reduce the efficacy of the hygienic cleaning process. This is where Surface Acoustic Wave (SAW) technology offers a cutting edge, new and improved flow measurement solution that we have harnessed with the innovative Bürkert FLOWave flow sensor.

What are surface acoustic waves?
Surface Acoustic Waves (SAW) were first discovered in 1885 and their properties have been examined for many years, with a great deal of modern technology adopting the principle. Surface acoustic waves occur naturally, such as in seismic activities.
We have used these effects in the patented technology used in FLOWave for the in-line flow measurement of fluids. As such, there is no need for sensor elements in the measurement tube, that come into contact with the medium, making FLOWave highly suitable for applications requiring the highest standards of hygiene and cleanability.
How do Surface Acoustic Wave sensors work?
FLOWave’s function involvesinter-digital converters which are stimulated by an electrical signal and generate Surface Acoustic Waves. These propagate across the tube surface and decouple into the fluid at a specific angle. The waves generate receive signals when passing through the fluid either once or multiple times. Both are carried out, in and against the flow direction. The time differences are proportional to the flow.
Applications of Surface Acoustic Wave devices
Applications of Surface Acoustic Wave devices like FLOWave predominantly involve hygiene and measurement of the flow of water with low conductivity. With additional development and expansion steps, we expect the new technology to be expanded to all other relevant applications. In parallel, application-supporting functions will be added to FLOWave to make it available as a multi-parameter device.
Advantages of Surface Acoustic Waves
There are many advantages of Surface Acoustic Waves. This technology means that FLOWave does not have any parts in the measuring tube resulting in:
- No pressure drop.
- No leakage problems.
- No dead spaces.
- No replacement parts.
- Greater independence from the medium.
With FLOWave, measurement is independent of flow direction and does not require conductivity of the medium. Its low weight, small dimensions and minimal energy requirements also reduce the installation effort and enable compact systems and cost savings.
If you'd like more information, please contact our team on +44 1285 648 720, email sales.uk@burkert.com or fill in the form below.