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ADT®-Monitored Motion Sensors

Learn about the device that helps keep uninvited guests out of your home.

ADT motion sensor

Worried about what’s happening at home when you’re not there? Each ADT-monitored security package from comes equipped with at least one motion sensor, so you can better safeguard possible entry points to your home.

So how do motion sensors work? What effect do they have on your home security? Read on to learn the answers to the most commonly asked questions about motion detectors.

Why Do You Need Motion Sensors?

It’s always a good idea to have protections in place to watch your back, whether you’re at home or not. Just one motion sensor can help secure an entire room, which saves you money on additional equipment and simplifies installation. Even the sneakiest intruder will find it difficult to slip past the advanced technology that powers ADT-monitored motion sensors.

How Do Motion Sensors Work?

ADT-monitored security systems rely on infrared energy given off by any heat source with a temperature above absolute zero (-459.67° F). That means nothing much escapes your system’s notice.

The ADT-monitored motion sensor constantly scans a radius up to 40 feet and immediately registers body temperatures of approximately 93° F. If there is a rapid change in an area’s infrared energy—such as someone walking past the motion sensor—it will pick up the change in energy, trigger the alarm, and send an alert to your ADT Command panel.

Things that shouldn’t trigger your motion sensors:

  • Heating or cooling your home (the change in energy is too slow)
  • Motion occurring outside a window (infrared energy cannot be detected through the glass)
Graphic showing how motion sensor works

Can Pets Trigger Motion Sensors?

It’s not uncommon for homeowners to worry about Spike running through a room and setting the motion alarm off by accident. Luckily, ADT has prepared for just such a scenario. Modern motion sensors can detect the approximate mass of a moving object, and ADT offers sensors with either 60 or 80 pound weight minimums needed to trigger an alarm.