Touching or looking through walls
Capacitive sensors are seen as the true all-rounders of level measurement technology: they are robust and suitable for many different uses because they can be used for detection of practically any medium.
In a robust all-metal housing they are also suitable for use in aggressive media with direct contact. If the medium does not allow direct contact, they can also see through (non-conductive) container walls. They are not troubled by adhesions or dirt, nor can the medium be contaminated by the sensor.