How Do Motion Sensors Work

Times are changing, and with the ever-evolving technology, people are progressively embracing new and modern innovations in security systems installation.

Regarding home security, gone are the days when dogs and watchmen were the only sources of security. Motion sensors are no different. Now we can rely on motion detectors to guard our homes, businesses and other property.

In this piece, you are going to learn how various motion sensors work.

Types of Motion Sensors To Consider


The microwave motion sensing technology uses microwave pulses to measure the reflections off moving objects. Once they have measured the reflections, the sensors will be able to tell whether or not the objects are moving. These kinds of sensors are very sensitive and can cover a larger target range.

However, due to their ability to see through non-metallic objects, sometimes microwave sensors can sense moving objects outside the targeted area. They also use a lot of energy and are easily prone to electrical interference according to

The electronic guard dog is one type of motion detector that uses this technology. This guard dog has no teeth and is not really visible. But place it in front of your house and any trespassers will be scared away by the angry barks.


Almost like the microwave motion sensing technology, ultrasonic sensors use ultrasonic waves to measure the reflections off moving objects. They are also very sensitive and can either be passive or active.

Passive ones are keen for specific sounds like glass breaking. Active detectors emit very high and unsettling sound waves to scare away intruders.

Passive Infrared

These sensors work by detecting the infrared energy (body heat) of the surrounding environment. All warm-blooded creatures emit this kind of radiation.

Once the system is armed, the motion sensors are activated by electricity.

Then, when a person or animal enters the targeted area, the sensors increase the temperature and create a protective grid.When the intruder persists and keeps on trespassing various grids, the motion sensors will eventually trip the alarm.

This type of sensing technology is very common in home security systems and indoor alarms. They are easily affordable and will last longer.

Dual Technology

This technology is a teamwork of both the ultrasonic and passive infrared technologies. Dual-tech motion sensors are often accurate, and that is why they are always preferred by big business owners and learning institutions. For the alarm to be tripped, both sensors have to sense intrusion.

Although each of the two combining technologies operates in different areas of the spectrum, they require just one mechanism to remain on. However, this dual trigger can fail to detect real alarms.


This motion-sensing technology relies on a focused beam of energy traveling between a sensor and an emitter unit. Therefore, when something moves between this unit of light, it interrupts the beam and triggers the motion detectors. More expensive sensors will use invisible infrared energy for this technology. One downside about photoelectric sensors is that they are prone to false alarms.

Get In Touch With a Professional

When you are interested in upgrading your home security, you should take some time to get in touch with local security companies ( try ) to get a better idea of the type of system that will work best for your specific needs.


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