For simultaneous monitoring of the minimum and maximum fluid levels in conductive liquids. The sensors (not included) can be easily manufactured with contact surfaces on the container wall or with rod or cable electrodes.

Functionality: Four electrodes are mounted in the liquid container, extending into the medium up to the desired switching point. The fill level is indicated by four LEDs according to water contact. When the container is completely empty, the red LED lights up. The lower electrode pair, for example, is used to control a filling valve. When the lowest electrode is released, the filling valve or pump is activated, and it is turned off again when the second electrode is wetted (hysteresis). The upper electrode pair serves the same functional principle to regulate the upper level, for example, of a pump. The second channel does not need to be used. The switching behavior of the evaluation (filling/draining) can be selected via two jumper bridges. The sensitivity of the electrodes can be adjusted using potentiometers. Two potential-free relays with changeover contacts are used to control the valves or pump.

Applications: Water replenishment and monitoring in rainwater cisterns, monitoring of condensate trays and compressor pressure vessels, boilers, springs and wells, livestock drinking troughs, pump control.