One of the typical applications for ultrasonic sensors is to monitor water level and provide an early indication when it reaches a critical point.
In one example, the USR6 short-range ultrasonic sensor is interfaced to a radio telemetry set in New England and is able to transmit pond level data to a remote site for monitoring.
In this outdoor installation, the sensor is mounted to a steel rod and points down at the water level, with no additional protection from the weather.
One of the questions we are frequently asked is whether the ultrasonic sensor can be mounted on top of a pipe and act as a still pipe. As with any application with many variables, it is difficult to offer a specific set of dimensions that would cover every situation. Please consider:
Longer lengths of a still pipe can allow water drops or hard water scale to form, leading to false level indication due to the returning ultrasonic echo. Therefore, make sure the inside of the pipe remains clean and free of any raised surface condition.