Brix series LCT-01 are capacitance type level transmitters. Vessel wall & probe forms two electrodes. If vessel is of non conductive material, the probe will be double rod type. The distance between electrode & 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 & vacuum have relative dielectric constant as 1 & that of liquids, it is greater than 1. The capacitance of the capacitor therefore depends on how much material lies between the probe & vessel wall i.e. Whether the probe is covered with or free from material. The capacitor changes with change in level of the material & provides corresponding 4-20 mA DC continuous output.