YK01, YK02 Series level switch is hoop fixed to the wall leading outside magnetic level gauge, level gauge using lead pipes on the liquid level float switch magnetic reed switch within the role, so reed pull or release , which corresponds to the binary output signal, YK03-type mechanical memory switch is running through the magnetic drive cam, drive micro switch, which outputs a binary signal. The switch signal can be directly imported PLC, flashing warning device or the Company after the KZ-based signal converter 220VAC direct access control. Alarm circuit to achieve the level of automatic control and alarm.