A CNC machine tool is an automated machine tool with a industrial control system that allows the machine to operate and process parts according to programmed procedures. It integrates the latest technology of machinery, automation, computer, measurement, microelectronics and so on, and uses a variety of sensors, the main sensors used in NC machine tools are photoelectric encoder, linear grating, proximity switch, temperature sensor, Hall effect sensor, current sensor, voltage sensor, pressure sensor, liquid level sensor, rotary transformer, INDUCTOSYN, speed sensor, etc. , it is mainly used to detect position, linear displacement and angular displacement, velocity, pressure, temperature and so on.

1.The requirements of CNC machine tools for sensors 

1) high reliability and strong anti-interference; 

2) to meet the accuracy and speed requirements; 

3) easy to use and maintain, suitable for machine tool operating environment; 

4) low cost. Different kinds of CNC machine tools have different requirements for sensors, generally speaking, large-scale machine tools require high speed response, medium-sized and high-precision CNC machine tools to require precision-based.

2. Application of Inductosyn Inductosyn Inductosyn is made by the principle that the mutual inductance of two planar windings varies with position. Its function is to change the angular or linear displacement into the phase or amplitude of the electromotive force, which can be used to measure the linear or angular displacement. According to its structure can be divided into two types of linear and rotary. The Linear Inductosyn is composed of a fixed length and a sliding ruler, which are installed on the machine bed, and the sliding ruler is installed on the moving parts and moves together with the worktable, the rotor is a rotating disk. The inductosyn has the advantages of high precision and resolution, strong anti-interference ability, long service life, simple maintenance, long distance displacement measurement, good workability and low cost. Rotary Inductosyn is widely used in machine tools and instruments of the turntable and a variety of rotary servo control systems.