The best Alarm security systems have a few essential qualities in common: they’re robust, they’re difficult to circumvent, and matched to the needs of the premise in question.

Alarm systems come in many different shapes and sizes, so you want to build a custom setup that meets your individual needs. Regardless of size, every Alarm security system should have these parts:

All alarm systems have a dedicated control panel. The control panel is the system brain; everything is wired or wirelessly connected to the control panel.

The keypad is the system interface. Usually placed near the main entrance or at critical checkpoints, this pad lets you turn on and off the system (usually referred to as “arming” and “disarming”).

The keypad often gives you information on what sensors detect activity or are not secure, an open window, for example.

These are typically magnetic sensors monitoring a connection between the door and the jamb or the window sash to the window casing. If the sensor contact gets interrupted by opening a door or window, the alarm will activate.

Glass break detectors are sound detectors that listen for the precise frequency of breaking glass. These sensors can trigger the alarm, even if the window contact sensor not interrupted.

Most indoor motion detectors include passive infrared (PIR) technology that only picks up the displacement of body heat. PIR prevents false alarms since spider webs and bugs will not activate the sensor. Outdoor motion detectors use passive infrared and microwave technology to catch intruders without getting false alarms from small animals.

A few types of motion detectors are available for security systems, but they fall into two distinct categories: Passive and Active. Active systems measure the presence of objects by sending and receiving a signal of some sort, while passive systems wait for changes to occur.

The most common are Passive Infrared or PIR sensors that detect rapid changes in the infrared spectrum. The heat from objects and people emits infrared light, invisible to the human eye but detectable by PIR.

Most PIR sensors use Fresnel lenses arrayed to focus the infrared light into the sensor, and when a rapid change gets detected across its field of view, it will send out a signal.

However, slow changes do not trigger the sensor, so it is theoretically possible to thwart them by moving very slowly. In practice, this threshold is impossible to determine on the fly, and security motion detectors are never the only system to defeat, so defeating a PIR is difficult.

Active motion detectors are less common but are still helpful for security purposes. Some use an emitter that sends a beam of light across a hallway or room into a photosensitive receptor. If the beam gets broken, the sensor sends a signal just like a PIR would. These are commonly seen at the bottom of garage doors, acting as a safety switch; if a person or object crosses the beam, the door stops moving.

Other active sensors use reflected ultrasonic waves to measure the environment. Sonar detectors emit a sound wave and measure the time and intensity of their return. A change to either triggers the alarm.

A similar sensor uses radar in the same way. Radio microwave pulses get sent out, timed, and measured on return.

CCTV surveillance cameras also act as motion detectors through rudimentary video analytics. When the camera detects an object crossing, entering, or leaving, it triggers the alarm.

The camera can begin recording, turn on lights, activate a siren or silent alarm, or send you a notification.

Using security cameras as motion detectors can cut down on a system’s complexity but may be limiting the security systems effectiveness if you don’t have independent motion sensors.

There are primarily two sensor technologies for detecting a fire, ionisation and photoelectric.

In an ionisation smoke detector, the surrounding air gets ionised by a slightly radioactive element (commonly americium-241). The alpha particles emitted by the americium charge air particles are allowed to flow into the ionisation chamber. The charged air particles move between two charged plates according to their new positive or negative charge, completing an electrical circuit. When smoke enters the detector, the ionised air bonds to the smoke particles, breaking the circuit and sending out an alarm. Ionisation detectors are best at detecting fires that are producing flames as opposed to smouldering fires.

Photoelectric (or optical) sensors, on the other hand, use a beam of light to detect changes in the air. The light can be visible, infrared, or ultraviolet and detects smoke based on the light scattering that occurs when smoke partially obstructs the light.

Photoelectric smoke detectors react better to slow-starting, smouldering fires than ionisation detectors, but despite some difficulty, they can detect flaming, fast-growing fires as well. Optical smoke detectors react to smoke earlier than ionisation detectors, making them the primary choice for commercial alarm systems.

The best alarm systems will have fail-safes to protect themselves from tampering. An interruption sensor will trigger an alert if any part of the system is taken offline, loses power, or fails to respond to a ping for any reason.

Panic buttons come in various shapes and sizes, but they all serve the same purpose: they allow you to activate the alarm or summon the authorities immediately.

Once your alarm system is up and running, will you subscribe to a monitoring service?

With most monitoring packages from commercial alarm monitoring companies, you have 24/7 access to a support centre that would respond to any alerts or alarms. They’re able to have emergency services dispatched or disarm the system in case of a false alarm.

The old alarm systems were self-contained and impossible to access from anywhere but the physical keypad. While this is nice and secure, it’s highly inconvenient when you want to use it from the other room or outside.

Ever forget to arm your security system before leaving? Modern alarms allow you to remotely arm or disarm the system, change its settings, or even check in on it while you’re out.

Likewise, you can also control electronic systems such as motorised gates, lighting or air conditioning.