... 3 wires; 3.CE certification. SG series Photo Switch,Photoelectrical Sensor 1, Principle:photoelectric sensor makes use of inspected object’ ... and auto protection for production line,serial signal,digital controller,etc.Function and struction can be changed ... of products, including Temperature Controller, Digital Adjustor,thermocouple (TC and RTD), Panel Meter, Sensor Meter, inductor, Power Meter, ...