What Kind of Home Security Motion Detector Is Right For Me?

What Kind of Home Security Motion Detector Is Right For Me?

The home security motion detector is the where the entire home security system is activated.  These are the “input” points for the entire system.  They initiate the signals that result in the alert or the alarm being triggered.  These sensors come in a variety of types and are based on various technologies.  Quite frankly, choosing the appropriate sensors is a critical step in planning your home security system.

Magnetic
These are the most common sensors in home security and are used as door and window alarms.  The device is installed so that a circuit is created when the door or window is shut.  When opened, the circuit is broken and the security system is triggered.

Infrared
Motion detectors are the second most common sensors in home security systems and infrared sensors are the most frequently used.  Sometimes called PIR (passive infrared) sensors, they are able to detect radiated body heat.  The cheapness and reliability of this sensor has made it standard in most security systems.

Shock (or Glass Break)
More commonly known as glass break sensors, these actually detect the shock wave created from breaking a window.  These devices are also known as “acoustic” or “sound” detectors.  Often they are used as a redundant monitor for the magnetic sensors mentioned above.

Dual Tech
One of the challenges in motion detectors comes from household pets.  How do these sensors discriminate between the movement of a person and that of a dog or cat?  Dual tech sensors combine the infrared with microwave technology (below) and are better able to be set to ignore animal movements.

Microwave
These sensors emit microwave energy to detect movement.  Some properties of microwave energy do not make it suitable for most home applications (such as penetrating through walls to pick up motion in other rooms).  Most commonly it is found as an automatic door sensor as you have seen in many businesses.

Ultrasonic
These sensors are either active (emitting high frequency sound) or passive (detecting sounds).  These sensors are among the most sensitive and therefore among the most expensive. They are not used in typical residential applications.

The purpose of all home security motion detectors is to first, detect motion, then to send a signal to the systems control panel which will in turn trigger the appropriate alert (a siren, a chime, a light, a phone call, etc.)  The most common combination of sensors in a standard security system are magnetic and infrared detectors.