Water level transmitter

The utility model relates to a water level transmitter including a power supply unit, a water level detection unit, a control output unit, and a CPU master control unit, wherein the CPU master control unit receives the low water level, middle water level, and high water level signals of the water level detection unit, and transmits a control signal to the control output unit based on the water level signals, the water level detection unit includes a first optical coupler isolation circuit, the water level signals of the water level detection unit are connected to the first general I/O port of the CPU master control unit via the first optical coupler isolation circuit, the control output unit includes a second optical coupler isolation circuit and a relay drive circuit, and the second general I/O port of the CPU master control unit is connected to the relay drive circuit via the second optical coupler isolation circuit. Trough the adoption of the first optical coupler isolation circuit in the water level detec