How do motion-sensor alarms work?

Volumetric motion sensors: a brief summary

• Motion sensors detect movements, changes in heat, or shifts in energy within a defined area.
• They can use infrared (PIR), microwave, or ultrasonic technologies to sense movement and energy changes in real time.
• These sensors trigger alerts the moment unusual activity is detected, when integrated into a volumetric detection system.
• They offer 24/7 coverage and early intrusion detection when paired with professional monitoring.

What are volumetric motion sensors, and how do they work?

A volumetric motion sensor is a type of motion detector designed to monitor a three-dimensional space, or volume, for any changes in movement, temperature, or energy. Volumetric detectors monitor these changes in a space in real time, to detect and verify physical intrusion.

Unlike pressure or perimeter sensors that protect doors or windows, these sensors protect the space itself, ensuring that any movement within the monitored area triggers an alert.

Here’s how these systems typically work:

1. Detection: movement or energy variation is detected within the sensor's coverage area.
2. Signal transmission: the sensor will immediately send a signal to the central alarm unit.
3. Verification: the control panel or monitoring centre verifies the cause of the alarm event, distinguishing between a genuine intrusion and a false alarm.
4. Response: if confirmed, the system triggers an audible siren, sends alerts to your mobile app, and, if applicable, a remote monitoring centre (like Verisure's 24/7 monitoring team) takes appropriate action.

In simple terms, a volumetric detector senses movement within a defined zone using infrared or microwave signals. It doesn’t rely on contact or pressure; instead, it picks up on any changes in energy patterns, allowing it to “see” movement through invisible waves.