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Alarm MonitoringSeptember 7, 2018

What Is A Movement Sensor?

Motion Detector in Corner

Security alarm systems play the most vital part in protecting homes and businesses. No alarm system can operate to its full functionality without one crucial component.

That being security movement sensors which are also known as movement detectors.

What is a security movement sensor?

A security movement sensor’s function is at it states in the name, it detects movement. These can also be called movement detectors. When your alarm system is armed and someone attempts to break into a room where a movement detector is located, this will trigger your alarms sirens and deter the intruder out of the premise.

Additionally if you have a monitored alarm system this provides real time information to showcase if an intruder is present, through multiple detections or triggers. Internal movement detectors have a range limit of around 15-20m, anyone moving within this range will be detected and the sirens will trigger.

Upon entering your premise the security movement sensors will trigger which commences a countdown grace period of around 10-20 seconds. This provides you the time required to enter your pin code in your alarm systems keypad, to disarm the alarm system before the sirens trigger.

What security movement sensor will suit me?

There are many different types of security movement sensors out there on the market. The key is to know which one is best suited to you. What type (hardwired or wireless) of security alarm system do you have? Do I have pets which I leave inside? Does my premise get really hot in summer? These questions will guide you in choosing what movement detector would best suit the protection of your premise.
Most of the different types of movement sensors come in hardwired and wireless options.
Hardwired Movement Detectors
These movement detectors communicate with the control panel (the virtual brain of your alarm system) via security cable. This means your movement detector powers off the control panel which is connected to the mains power source.

  • Never need to replace batteries
  • No signal issues, no matter the distance from the control panel
  • Compatible with multiple branded detectors types

Wireless Movement Detectors
These movement detectors communicate with the control panel via a wireless receiver which is installed in the control panel. Similar to how phones connect to wireless networks for internet connection, that is how wireless movement detectors communicate with the alarm systems control panel.

  • Greatest flexibility in where detectors can be positioned, without worrying about the cabling requirements
  • Quick installation time, saving labour cost
  • Easy transferability when moving premise

4 Types of Security Movement Detectors

Passive infrared Movement Detectors

Most commonly available movement detectors, that measure the heat levels emitted from objects which come in the form of infrared radiation. When a movement detector is armed it will be covering an internal area which is all relatively the same temperature. In the event a human or animal walks into this area a sudden temperature change is detected, causing the detector to trigger the alarm sirens.

Similar temperature objects may not trigger the movement sensor rather the change in the objects shape will trigger the detector.
Dual Technology Movement Detectors
These detectors only trigger when two technologies are triggered together. The first technology being the passive infrared detection we mentioned above. The second is microwave technology which emits microwaves that bounce back at a certain frequency, so when something moves into these waves this disrupts the flow and will trigger the alarm sirens.

False alarms are reduced with rapid temperature changes in the summer months as the infrared technology may be triggered but there is no microwave disruption from any moving object. Meaning the alarm sirens will not trigger unless both variables are activated.
PET Friendly Movement Detectors
Many families today own pets and this is preventing them from arming their alarm system, in fear that the alarm sirens will trigger and scare the pets. Technology has now evolved to prevent your pets from triggering your alarm system whilst armed. Pet friendly detectors are smart enough to measure weight mass of objects, in the event there is a moving object under the set weight mass this will not trigger the sirens. Most sensors can safely operate without triggering the alarm system for pets less than 20kg; there are also heavy duty detectors available for those who own larger pets.
Outdoor Movement Detectors
These movement detectors have a reduced detection range compared to internal movement detectors to avoid false alarms from stray birds or animals. Most commonly they are positioned facing the immediate ground area so if anyone or animal moves within a specific front door entry area or rear window this will trigger the alarm sirens.

Why are movement detectors essential?

Movement detectors are essential in protecting your premise as these devices trigger the security systems sirens. Movement sensors are especially important when your alarm is monitored back to base. The Victorian Police have passed legislation where they have the right not to respond to any alarm system unless multiple movement detectors have been triggered. Victoria Police also advise that you should only have any security system installed by a licensed security installer.

New Victoria Police procedures were put in place to prevent false alarm call outs. When multiple movement detectors are triggered this means someone could be moving around the premise which is sufficient evidence to elicit a police response. It’s best to check your local states police website to see the different state regulations for alarm responses.

Summary of key benefits


  • Movement sensors ensure your premise is protected and prevents any criminal from entering.
  • Hardwired detectors never require battery replacement and other branded types of detectors can be used.
  • Wireless detectors save money and can simply be transferred to a new premise if required.
  • When having a monitored alarm your movement sensors can trigger multiple times which can authorise a Police response in Victoria, this prevents false alarm callouts.
  • You can leave your pets inside whilst leaving your alarm armed with pet friendly detectors.
  • Outdoor movement detectors deter criminals before they can knock on a door or window.

Motion sensors are a core component of any alarm system to be installed. No matter if it’s a home or business that needs to be protected, movement detectors are the main triggers for your alarms sirens. Without movement detectors you will have a security system that doesn’t protect your premise.

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