Proximity switches are widely used in aviation, aerospace technology and industrial production. In daily life, such as hotels, restaurants, garages, automatic doors, automatic hot air blowers have applications. In terms of security and anti-theft, such important places as data archives, accounting, finance, museums, and vaults are usually equipped with anti-theft devices composed of various proximity switches. In measurement technology, such as length and position measurement; in control technology, such as displacement, velocity, acceleration measurement and control, a large number of proximity switches are also used.