Know the Proximity Sensor

"Proximity sensor" includes all sensors that perform sensing / detection in non-contact, compared with a sensor, such as limit switches, which detect objects by physical contact. Proximity Sensors convert information about the movement or presence of an object into an electrical signal. There are three types of detection systems that perform this conversion: a system using eddy currents generated in the metal object by electromagnetic induction sensing system that detects changes in electrical capacity when sensing object approaching, and a system that uses magnets and reed switches.

Japanese Industrial Standard (JIS) defines a proximity sensor in JIS C 8201-5-2 (low voltage switch gear and control gear, Part 5: Control circuit devices and switching elements, Part 2: Proximity sensor), in accordance with IEC 60947-5 -2 translation of non-contact detection switch positions.

JIS provides the common name "proximity sensor" for all sensors that provide non-contact detection of target objects that are near or within the vicinity of the sensor, and classify them as inductive, capacitive, ultrasonic, photoelectric, magnetic, etc.

Technical guidelines define all inductive sensors are used to detect metallic objects, capacitive sensors are used to detect metal objects as well as non-metallic, and magnetic field sensor utilizing DC as a Proximity Sensor.