The liquid level switch is a kind of controller which can keep the water level constant by opening the valve of discharging or entering water according to the signal output of the liquid level sensor. It can also be said that the liquid level switch outputs a kind of switch signal.
The liquid level switch first determines the height of the liquid level, and then outputs the switch signal according to the height. The liquid level sensor converts the height of the liquid level into the form of electrical signals for output. We can process electrical signals such as plc, data collector or professional display to output liquid level. The principle of the level switch and the level sensor is the same. But the liquid level switch is a switch control circuit, and the liquid level sensor is equivalent to the circuit components used for voltage and current conversion.