Control panels; key pads; contacts. What are these? What do they do? Understanding the functions of the numerous components of a security alarm can be daunting. Below is a quick overview to aid you in your comprehension of the common parts of a security alarm. There are three main categories under which almost all security alarm components fall: controls, sensors, and output devices.

Controls:

Control Panel -- the hub of your security alarm. All security alarm sensors are connected to the control panel. It interprets the signals received from the sensors, and in turn alerts the security alarm output devices which either summon aid or sound warnings.

Key Pad -- allows you to interact with your security alarm. It is the primary way to turn your security alarm on and off; it is also how you notify your security alarm control panel of personalized upgrades that you have made, such as additional sensors and output devices.

Sensors:

Contacts -- detect the opening and closing of doors and windows. Contacts alert your security alarm control panel when the magnetic bond between the door frame and the door or the window sill and the window is broken.

Glass Break Detectors -- detect the breaking of windows or glass doors by listening for the specific sound frequency of breaking glass. A glass break detector will alert your alarm system if glass is broken within approximately 35 feet of the detector.

Motion Detectors-detect movement within a pre-set range of a given environment. Motion detectors are one of the most important and widely used security alarm sensors.

There are five types of security alarm motion detectors:

Infrared Motion Detectors -- use infrared or passive infrared (PIR) sensors to alert your alarm system to certain changes in the levels of heat and/or movement in a particular room or space.

Corner Mounted Motion Detectors -- the most commonly used motion detector on the market, and are included with the majority of security alarm systems. Positioned in the corner of a room to offer a wide range of motion detection.

Ceiling Mounted Motion Detectors -- alert your security alarm to virtually all movement because they give full-360º coverage. Especially useful in rooms in which corner mounted detectors would be blocked by doors, shelves, or other stationary objects.

Pet Immune Motion Detectors -- use PIR technology and only alert your alarm system when large changes in temperature are detected, not the smaller changes made by pets.

Outdoor Motion Detectors -- detect when a person or vehicle is within a certain range of the motion detector and alert your alarm system to turn on lights.

Output Devices:

Sirens -- emit a loud piercing signal when triggered by the alarm system control panel. Mainly used to scare off potential burglars or trespassers. Strobe Lights -- repeatedly flash on and off when alarm system sensors detect an intruder