Dual Tech Motion vs. Traditional Motion

A dual-tech motion sensor detects movement using both passive infrared (PIR) and microwave sensors. It will only activate if both sensors are triggered. A traditional motion sensor detects movement using only a PIR sensor. A traditional motion sensor may also be called a PIR motion sensor.

When choosing a new motion sensor, you will likely be wondering whether you should get a dual-tech motion sensor or a PIR motion sensor. Really, both sensors will do the same thing. They will detect movement and alert the alarm control panel when activated. The difference is how they complete this task. With a traditional motion detector, there is only an internal PIR sensor. But with a dual-tech motion detector, there is both a PIR sensor and a microwave sensor.

A PIR motion sensor works by looking for changes in infrared (IR) energy that occur with movement. Every person and object gives off a small amount of infrared energy. When a person or object comes within the sensor's field of view, the sensor will detect a change in IR energy. This will activate the sensor and tell it to alert the system. This works very effectively and reliably when the sensor is mounted properly. The problem is that things like a moving ceiling fan, intense sunlight from a window landing on a wall or hot flowing air from a vent can potentially cause a large enough change in IR energy to activate the PIR sensor. This is why it is very important to choose a proper location for a PIR motion detecting sensor.

But with a dual-tech motion sensor, there are two (2) internal sensors. There is a PIR sensor and a microwave sensor. The PIR sensor works as described above. The microwave sensor sends out continuous microwave signals. These signals will bounce off of objects in the area, and the sensor will monitor their pattern. If the pattern changes, then the sensor will know that movement has occurred. However, a dual-tech motion detector will only activate if both the PIR sensor and the microwave sensor have been triggered.

The reason why a dual-tech motion sensor works so well is because factors like hot flowing air from a vent and intense sunlight landing on the wall will never activate a microwave sensor. Even if they manage to trick the PIR sensor, this will not happen with the microwave sensor for a dual-tech motion detector. This makes false alarms much less likely to occur on a dual-tech motion sensor than a traditional PIR motion sensor.

It's worth mentioning that there is no such thing as a "microwave-only" motion sensor. This is because microwave signals can actually travel through walls, and they could potentially respond to movement that occurs outside the building. This would result in too many false alarms. A dual-tech motion detector needs the PIR sensor as somewhat of a "check" to the microwave sensor. Even if motion occurs outside the building and triggers the microwave sensor, this will never trigger the PIR sensor. By using its PIR sensor and microwave sensor together, a dual-tech motion detector can accurately respond to movement, while not causing any false alarms on the system.