CLT : Capacitance Type Level Transmitter

A capacitance is formed between the probe and the vessel wall.As the level of the measuring medium rises or falls capacitance between the probe and vessel wall changes proportionately. A high frequency sine wave is applied between the probe and tank wall. A change of medium level will induce a change in the current of the applied sine wave. From when the capacitance in the vessel increase, impedance will decrease and current will increase and vice-versa. (Z=Resistance,C=Capacitance, F= Frequency)
Head mounted electronics converts the capacitance variation to 4-20mA signal for long distance transmission. It is provided with trimpots for SPAN and ZERO adjustments. With no moving parts it is free from wear and tear, rugged and robust in construction. No dead zone like float based instruments.
It must be ensured that the probe is parallel to the tank wall throughout it's length.