... /3 wires,AC 2/3 wires; 3.CE certification. SG series Photo Switch,Photoelectrical Sensor 1, Principle:photoelectric sensor makes use ... or logicgate.Widely used in process controling and monitoring system for spacing,positioning detection,auto counting,speed and auto ... reflection,opposed type,and tank type,Shape:mainly round,pacake,column,tank,depend on different use occasions and measurement.3, ...