The principle of detection involved is the capacitance phenomena which is developed between the probe and the reference. The amount of capacitance developed in any vessel is determined by the size (surface area) of the probe, the distance from the probe to its ground reference, and the dielectric constant of the medium being measured.
The amount of capacitance developed in a vessel becomes dependent upon the amount of the probe which is covered with media. As the media rises and falls in the tank, the amount of capacitance developed between the probe and the ground reference also rises and falls.
This change in capacitance is detected by employing radio frequency (RF) and converted to a digital waveform proportional to the change in level which in turn is used for level Detection and monitoring.