Proximity sensors are a general term for sensors that replace contact detection methods such as limit switches for the purpose of detecting objects without touching them. It converts the movement and presence information of the detected object into an electrical signal. Among the detection methods that convert into electrical signals, there are methods that use eddy currents generated in the metal body of the detection object caused by electromagnetic induction, methods that change the capacity of electrical signals caused by the proximity of the trapped object, and methods that use sharp stones and guide switches. The products that can also detect the proximity of an object and the presence or absence of a nearby detection object in a non-contact manner in sensors are called “proximity switches ” and consist of inductive, capacitive, ultrasonic, photoelectric, magnetic, and other types.