Glossary Updates12 new terms added to the glossaries · October 2, 2026, 22:44 CEST
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Glossary · Sensors and measurement

Proximity sensor

Also known as: Proximity switch, Proximity detector

German: Näherungssensor

In industrial automation, a proximity sensor is a sensor that detects the presence of an object within its sensing range without physical contact, using inductive, capacitive, magnetic, photoelectric or ultrasonic principles.

  • Sensors
  • Standards

In one sentence

A proximity sensor detects objects within its sensing range without contact, using inductive, capacitive, optical, magnetic or ultrasonic principles.

Example

A proximity sensor detects each tooth of a gear to monitor the speed of a conveyor drive shaft.

How it applies

  • Engineering: IEC 60947-5-2 covers proximity switches and defines terms such as rated operating distance and assured operating distance. Output types (PNP, NPN, NO, NC, analog, IO-Link) must match the input card.
  • Commissioning: Check switching distance and function with the real target under operating conditions.
  • Safety: A standard proximity sensor is not a safety component. For guard interlocking or presence sensing, devices designed for safety, such as coded safety sensors or a Presence-sensing device (PSD), are used within a designed safety function.
  • Documentation: List proximity sensors with their function, type and switching distance in the spare parts list, since a sensor with a different output type fails silently.

Proximity sensor vs. presence-sensing device

In machine safety, a Presence-sensing device (PSD) detects persons for safeguarding. A proximity sensor detects objects for process control.

By knowledge.aitechdoc.world · Published September 26, 2026 · Last reviewed

Source: IEC 60947-5-2, Low-voltage switchgear and controlgear — Part 5-2: Control circuit devices and switching elements — Proximity switches

Definitions follow the cited standards and specifications. Where a source is a copyrighted publication, such as an ISO, IEC or EN standard, the definition is a close paraphrase, not a verbatim quotation, so as not to infringe copyright. We recommend reading the original publication. The sections “How it applies” are editorial commentary by AI TechDoc Blog and are not part of any standard.

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