It is a simple, low cost, point level controller designed for detection of conductive liquids, having low densities, high viscosities, containing solid particles and interface between nonconductive and conductive liquids.
Operation:
It comprises of a probe, wired to a level controller. The probe holds one common "Mass Electrode" and one or multiple "Control Electrodes" depending upon the number of levels to be controlled. All the electrodes are suitably insulated to avoid electrical bridging. The lengths of "Control Electrodes" correspond to the height of preset level points to be controlled and the length of the "Mass Electrode" is kept Slightly longer than the longest "Control Electrode". If tank is conductive, it can be used as a "Mass Electrode".
Then number of control electrodes equals number of preset levels. Level controller houses sensing electronics consisting of power supply and signal conditioning circuit which provide
A "Low AC Voltage" across mass and control electrodes. On liquid reaching preset level point electrical circuit gets completed generating a signal which is amplified to actuate a relay, whose potential free contacts are available for, subsequent operations. On "Level Falling" the circuit breaks, cutting out the relay.
Features:
When the liquid level rise in the tank, the liquid also rise inside the glass tube carrying a graduated pointer. The liquid level in the tank can be conveniently read against the pointer.