What is an ultrasonic water level sensor?

An ultrasonic water level sensor is a non-contact device that measures the height of water in a tank, reservoir, or open channel by using ultrasonic sound waves.

Key features include:

  • Non-contact – nothing touches the water, so there’s no risk of contamination or corrosion.
  • Works with clean or dirty water – suitable for reservoirs, rivers, sumps, and sewage treatment.
  • Continuous measurement – gives real-time data rather than just a high/low alarm.
  • Integrates with control systems – can send analogue signals (e.g. 4–20 mA), digital outputs, or connect via MODBUS/IoT.

How does an ultrasonic water level sensor work?

  1. The sensor (mounted above the water surface) emits a short burst of ultrasonic pulses.
  2. These pulses travel through the air, reflect off the water surface, and return to the sensor.
  3. The sensor measures the time delay between sending and receiving the echo.
  4. Using the speed of sound in air, the device calculates the distance to the water surface.
  5. Knowing the tank’s dimensions (or reference point), the system converts this into a water level reading.

What are typical applications for a ultrasonic water level sensor?

  • Monitoring water levels in storage tanks, silos, and sumps.
  • Flood warning systems in rivers, canals, or drainage systems.
  • Wastewater treatment plants for managing inflow/outflow.
  • Irrigation systems to track reservoir levels.
  • Hydroelectric plants to monitor dam and reservoir levels.

Need more information about ultrasonic water level sensors?

Contact Deeter today for further support on ultrasonic water level sensors.