The USW02 is an acoustic level sensor for measuring the sea surface. It emits sound waves that bounce off the water. By timing the return, it calculates the distance. Internal temperature and humidity sensors correct the reading in real time. It has a long service life and a low cost, and its refresh rate makes it suitable for wave monitoring. It connects to a SpaceEcho station and reports to EchoCloud.
USW02 acoustic level sensor mounted on a pier above the water (illustration).
Features
Built-in correction
Temperature and humidity sensors adjust the reading for the speed of sound.
6.6 Hz refresh rate
Enough to follow waves.
11° beam angle
A narrow beam aimed at the water surface.
Cost-effective
A lower-cost option for level and wave monitoring.
Specifications
Measuring range
28–700 cm
Beam angle
11°
Accuracy
±1 cm
Refresh rate
6.6 Hz
Output interface
Analog; digital Modbus RS-485
Supply voltage
12–36 V DC
Choosing a level sensor
A SpaceEcho station can measure water level with three sensor types. The right one depends on the site, the range and the accuracy needed.
Piezometric — PSL03
Submerged. Works where nothing can be mounted over the water, and is not affected by air temperature, fog, spray or foam on the surface. Limits: range of 5 m, accuracy of ±0.5 % F.S., and the probe is in contact with the water, so it needs cleaning and checks against a reference level. See the Piezometric Level Sensor.
Radar — RW04
Non-contact, from above. Range 0.1–40 m, accuracy ±2 mm, IP68. The measurement does not depend on air temperature or humidity. Limits: it needs a mount over the water with a clear view of the surface. See the Radar Level Sensor.
Ultrasonic — USW02
Non-contact, from above. Range 28–700 cm, accuracy ±1 cm, with built-in temperature and humidity correction. A lower-cost option for level and wave monitoring. Limits: shorter range and a wider error than radar, and the beam (11°) needs a clear path to the water.
