How Do Security Motion Sensors Work?

Last Updated on 8 November 2023

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.

Motion Sensors Basics: Definition & Uses

Motion sensors, sometimes referred to as motion detectors, are defined as electronic devices that are designed to detect movement. They’re often integrated into products such as lights, alarms, security cameras, and most recently, smart doorbells. When motion sensors detect movement, they trigger the device they’re attached to.

Motion Sensors vs. Cameras

Some people wonder, “Do motion sensors and detectors have cameras?” The short answer is no – motion sensors work by using ultrasonic sound waves, not camera images. The sound waves bounce off surrounding objects, creating an impression of the nearby landscape. When those sound waves are interrupted, changing the impression, the sensor is triggered. This technology can be useful when incorporated into security cameras, allowing them to pinpoint moments of interest.

While many security cameras do have motion sensors, relying solely on motion detection can result in many false alarms. Instead, look for security cameras that use infrared heat sensors for more accuracy. As security camera 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 and True Detect™ Infrared Technology

PIR or Passive Infrared motion sensors are designed to reliably detect people, large pets & other large, warm, moving objects. Security cameras with PIR technology 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 – it’s also thermal heat sensing. The True Detect PIR sensor is triggered when a security camera senses heat, whether coming from people or cars. True Detect ensures that your security notifications are more accurate, as there are fewer false triggers.

What are Door and 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 while the system is armed. Door and window security sensors come in two magnetized pieces, one of which attaches to the door or window, while the other attaches 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 that can trigger a call to check on your home. For some people, this 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 very costly. Instead, many people choose to install sensors on their 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 are good, we always recommend installing security cameras at your home’s entry and exit points.

Getting Started with Security Sensors

Now that you’re familiar with how motion sensors work in cameras and security systems, you can start to explore our DVR and NVR security systems to address all of your home security needs, including your first priority – securing 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.

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