The Level control system is designed using a mechanism with very low friction. The output can be either (a) digital or (b)analog.
a)The digital solution is easy to setup, the switches can be registered for achieving a very tight range. Two switches for level high and level low. Two switches for level very high and level very low.
b)The analog solution give an output 0-10 Volts or 4-20 mA. Two switches for level very high and level very low.