The TDC-GP30-F01 from ams is a water flow sensor that includes an ultrasonic flow measurement front end, a low-power 32-bit processor and firmware for converting the sensor’s analog outputs to measurements of cold water flow, volume and temperature. This means that you can design an ultrasonic water meter based on this device without developing any firmware, you only need to characterize your spool pieces.

The chip provides a direct connection to ultrasonic transducers, and only requires the addition of a simple microcontroller to operate a water meter’s peripheral functions, such as a display and connectivity. If the built-in software is not good enough for you, you can add your own code. 

The device measures the difference in the time it takes ultrasound waves to travel upstream and downstream, providing extremely repeatable, temperature-stable and accurate timing measurements. The very high precision and stability of its flow measurements mean that it is able to detect water leakage rates as low as 0.5 liters per hour, many times lower than the minimum water flow measured by today’s widely used mechanical water meters. The high precision of the sensor makes it suitable for use in water metering applications that are regulated by law.