Rain Bird® M80131 UFS150 Ultrasonic Series 1.5" Flow Sensor. The winner of the Irrigation Association 2022 New Product Contest, Rain Bird's Ultrasonic Flow Sensors (UFS) represent the best in flow sensing technology for irrigation, sending flow data to central control or stand-alone controller systems for precise and accurate flow monitoring. The Ultrasonic Flow Sensors use ultrasonic waves to sense flow rate, as opposed to the impeller (paddle wheel) design of traditional flow sensors. This enables the Ultrasonic Flow Sensors to read a wider flow range, eliminates the typical straight-pipe requirements of standard flow sensors, and allows the sensor to remain installed during winterization with pressurized air blowout.