Motion & Security Sensors Explained


Last Updated on 12 October 2022

Many home security systems include motion and security sensors; however, there are different types of security sensors. Our security experts explain the various security sensors and what you need to know.

What is a Motion Sensor?

As the name implies, motion sensors detect moving objects outside or even inside your home. They are often tied to lights, alarms, security cameras, and most recently, smart doorbells.  Motion sensors are integrated into other products to detect and trigger a response such as the light turning on or the camera commencing recording. The purpose is to trigger an alarm, light, or camera recording to deter or catch criminals. 

Swann True Detect Heat SensingWhile motion detection is a good first step, relying solely on motion sensors can result in false alarms. Instead, look for a security system that uses infrared heat sensors for more accuracy. As security systems often notify you when they are triggered, infrared heat sensing ensures you won’t be bombarded by unnecessary notifications. When looking for a security camera with infrared technology there are two options on the market, PIR and True Detect™.

  • PIR or Passive Infrared motion sensors are designed to reliably detect people, large pets & other large warm moving objects. Security cameras with PIR technology means security cameras are smart enough to detect people and security threats as opposed to a tree branch blowing in the wind.
  • True Detect™ is more than just motion sensing but also includes thermal heat sensing. The True Detect PIR sensor is triggered when a security camera senses heat whether from people or cars. True Detect ensures that security notifications are more accurate as there are fewer false triggers.

What are Door & Window Sensors?

Door and window sensors are one component of a home security system. Their primary function is to set off an alarm if a door or window is opened when the system is armed. Door and window security sensors come in two magnetized pieces, one which attaches to the door or window and the other to the frame. It’s important to note that most door sensors will detect the motion of the door, but not any other movement around it.

Many professionally monitored security systems include door and window alarms to trigger a call to check on your home. For some people, the follow-up call is a key benefit of a monitored security system. Whether you choose a DIY or professionally monitored security system, you can install door and window alarms to boost your home’s security. 

Where to Install Door & Window Sensors?

You could install sensors on every single door and window, but that can be a very costly option. Instead, many people choose to install sensors on the ground floor windows to be more economical. In addition, you can add door sensors to the main entry and exit points of your home such as the garage door, back door, or front door. While sensors a good, we always recommend installing security cameras at your home’s entry and exit points.

Security sensors can boost your security system, but the priority is to first monitor and secure your entry and exit points. Not sure what this means or how to get started? Use our home security checklist to learn the top three things you need to secure your home.


  1. I have 2cocker spaniels
    If I install the sensors on door jam about 1m above ground level parallel to the ground will it detect the dog going through the doggy door

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