Non- Invasive Ultrasonic Sensors are designed to detect liquids through the metal wall of a container or tank. These Ultrasonic Sensors generate a high frequency ultrasonic pulse whose echo is detected and evaluated by the sensor. These Ultrasonic Sensors compare the actual echo with the taught curves representing the empty and filled status of the container und sets the output accordingly. Non- Invasive Ultrasonic Sensors indicate electrical or acoustic interference or a sensor failure due to insufficient coupling by a light emitting diode and an alarm output.
