... 2/3 wires,AC 2/3 wires; 3.CE certification. SG series Photo Switch,Photoelectrical Sensor 1, Principle:photoelectric sensor makes ... , Voltage Meter, Ampere Meter, Counter, Tacho Meter, Frequency Meter, flowmeter,Timer,Timer Relay, Solid State Relay, Proximity Sensor, ,Pressure sensor ,load cell ...