SoundWater’s promise to you is that our products provide measurements you can trust. Our proprietary SoundWater Reciprocity Architecture™ prevents zero-flow drift and eliminates the need for calibration, resulting in long-term measurement stability and accuracy.

Zero drift is a phenomenon that occurs in all measurement devices, and if not controlled can result in measurement error. In the case of flow meters, zero drifting can cause phantom flow (registered flow totalized when there was no flow), and/or added measurement error. In addition, uncontrolled zero drift may require frequent calibration. All of this ultimately leads to low confidence in your measurement.

The causes of zero drift can come from many sources, but ultimately the symptom is that the ultrasonic signal from the upstream transmission does not match the ultrasonic signal from the downstream transmission. For example, the two received ultrasound signals are not identical and leads to a measurement where none exists. Thus, as a system (flowmeter, pipe, fluid, temperatures, etc.) changes over time the zero may also drift accordingly and unpredictably.

To correct this common problem with flowmeters, we have implemented a special theorem from Electrical Network Theory called Reciprocity. Reciprocity, like Tellegen's theorem, describes a way in which the output of a reciprocal system may be held identical despite changes to the system.

Why doesn't everyone do this? Reciprocity may seem straightforward on paper, but when implementing it in real-world electronic hardware, it is quite the opposite. It is extremely difficult to do! At SoundWater, we find Reciprocity essential to what we do, so we have put in the time, effort, and development costs to perfect the technique over the last seven years. Yes, it took us that long to get it right!

To us, it is not okay to ask customers to zero calibrate a flowmeter every time they install it. That takes too much time and it is sometimes not possible to shut down a process. Also, if the zero is drifting around this may cause phantom flows, and/or errors in the flow measurement causing customers pain and time.

Ultimately, not having Reciprocity was not an option. Reciprocity is perfectly aligned with what we believe in and what we are doing here at SoundWater. Everything must be quick, easy, and correct!

With Reciprocity in our hardware, our end users:

• do not need to calibrate at each installation

• do not need to calibrate annually

• will not have phantom flow

• will not have zero drift

• WILL have confidence in their measurement

This is the right way to build a flowmeter.