CNC machine tool is an automated process control system equipped with machines, according to the program has been programmed, so that the machine action and machined parts. It combines mechanical, automation, computer, measurement, microelectronics and other latest technology, using a variety of sensors, sensor applications on CNC machine tools mainly photoelectric encoders, linear encoders, proximity switches, temperature sensors, Hall sensors, current sensor, voltage sensors, pressure sensors, level sensors, rotary transformers, induction synchronizer, speed sensors, etc., mainly used to detect the position, linear displacement and angular displacement, velocity, pressure, temperature, etc. ??? CE product safety certification mark major steps ??? (1) design products so that compliance with the relevant product safety standards ??? (2) to establish the technical documentation (TCF) (that is, to confirm that the product complies with all relevant CE certification basic safety requirements of the Directive, and specific information display) ??? (3) the implementation of quality assurance system ??? (4) to perform validation or signed by a certification body approved by the self-declared compliance statement (certain products shall be nuclear The verification mechanism can be attached only after approval CE certification mark) ??? (5) CE certification label attached.?