---
title: What is a Passive Infrared (PIR) Sensor?
description: Find out what a Passive Infrared Sensor is and its role in your business security system.
---

[DGA Blog | Business Security and Fire Systems](https://blog.dga.com)

# [What is a Passive Infrared (PIR) Sensor?](https://blog.dga.com/what-is-passive-infrared-sensor)

 Written by [Isabel Leckie](https://blog.dga.com/author/isabel-leckie) | 2/22/24, 1:00 PM

A Passive Infrared (PIR) sensor is a type of motion sensor. This technology operates by detecting movement within a specific area by measuring the infrared radiation emitted by objects.

PIR sensors are most useful when they are integrated with an access control system. When a person approaches a door from inside the protected area, the PIR sensor detects their presence, triggering the access system to temporarily unlock the door. This seamless process ensures an efficient exit while maintaining a high level of security.

[View full post](https://blog.dga.com/what-is-passive-infrared-sensor)

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