Capacitance Level Transmitter
Product Details:

Model	LCT-01
Color	Blue
Isolated Power Supply	24 V DC, External
Process Connection	1) 1 inch BSP Threaded 2) 1 inch ASA 150, Flanged
Accuracy	+/- 1% F. S.
Output	1) 4 to 20 mA DC, 2 Wire 2) 0 - 5 V DC

Electronet series LCT-01 is Capacitance Type Level Transmitters. Vessel wall and probe form two electrodes. If the vessel is of nonconductive material, the probe will be the double-rod type.
The distance between electrode and surface area of electrodes remain unchanged. The variable is the depth of the material being measured which represents the dielectric constant between two electrodes. Air and vacuum have relative dielectric constant as 1 and that of liquids, it is greater than 1.
The capacitance of the capacitor, therefore, depends on how much material lies between the probe and vessel wall i.e. whether the probe is covered with or free from the material. The capacitor changes with a change in the level of the material and provides corresponding 4-20 mA DC continuous output.