Presence sensor: what it is and how it completes your alarm 2026

Installing an alarm is one of the best options to increase the security of your home or office. When it comes to choosing the most suitable one, there are a variety of devices you can choose from.depending on what your needs are.

For example, if your house is located in a surrounding plot , a perimeter alarm can be a good decision.

Of all the types of alarms that you can install, some have presence sensors. It is abouta device that many discard because they have pets, which can set off the alarm at the wrong time.

However, they can be configured to be compatible with the presence of animals.

Keep reading to find out exactly what a presence sensor is, how it differs from a motion sensor, and how it complements your alarm.

What exactly is a presence sensor?

A presence sensor or detector is most often confused with a motion sensor.

It is true that these are two devices with many similarities that, we could say, belong to the “same family.” However, there are some differences between both.

Motion sensors are elements that detect the heat of people or objects moving through a infrared system. They are designed to activate and send an alert when they detect movement through said system.

Its main function is totrigger an alarm as soon as this detection occurs.

For their part, sensors or presence detectors differ from the previous ones because they have greater sensitivity. This is because they detect not only heat, but also light, and continuously.

In addition to being used as a complement to a surveillance system, it alsocan activate lights, air conditioning or ventilation. As for its operation, it is not only based on infrared technology, but there are others.

How do presence sensors work?

These devices can work with different types of technology. In any case, their activation occurs when they detect any movement in the space in which they are located.

These are the different types of presence detectors:

1. Infrared presence sensors: As in the case of common motion sensors, these detect the temperature of the space. They appreciate the variation that occurs with the presence of a person, since body heat raises the average.

If the movement occurs in their field of vision, they perceive it with greater precision, which is why they are not the most suitable devices for capturing small movements.

However, this makes them more compatible with the presence of pets. They are also known as passive sensors.

1. Ultrasonic presence sensors: La tecnología de estos dispositivos es mucho más avanzada que la anterior, lo que los hace más sensibles al movimiento de cualquier objeto o persona. In essence, these devices distinguish the frequency between the emitted wave and the received one.

Vibrations or air currents can make them jump, so these are not recommended if you have animals at home.

If you decide on this option, it is important that you remember to leave the windows tightly closed, as the current could activate them. Unlike the first, these are active sensors.

1. Dual presence sensors: The latter are the result of combining the two previous technologies, which makes them the most sophisticated and, of course, effective.
   Consequently, they are also the most expensive. They are those used, for example, in professional environments such as security companies.

Presence sensors and alarms

Within the broad concept of what an alarm is, presence sensors are simply elements that complement them and that can be combined with others such as, for example, video surveillance cameras.

For practical and security purposes, the more detection elements an alarm system has, thethe greater its effectiveness. So installing cameras, although it is the option chosen by many, may not be enough if what you are trying to protect is a large space.

In these cases, you can install presence sensors in parallel that expand the detection range. Presence detectors have, however, many other applications.

They are, therefore, a great choice to place in the windows of your home, since they would send an alert in case a glass breaks or if they manage to open it from the outside.

On the other hand, these sensors can also be used connected to a spotlight. This is an option chosen by many, who instead of an alarm that emits a loud noise, prefer to protect themselves with a strong light to avoid causing discomfort to the neighbors.

Especially outdoors, high-power lights work as a deterrent.

Tips for installing presence sensors

If you buy a motion detector, first evaluate the characteristics of the space in which you intend to place it. Depending on the layout and where the entrance is located, you will know if a ceiling, wall, surface or recessed sensor is best for you.

It is convenient to install itat least at a height of 2.5 meters, and place it in the place where the detection angle is as large as possible. The latter is important not only for security, but because presence sensors have a utility beyond warning about the presence of intruders.

These devices canbe linked to the HVAC system, air conditioning or lights of the home. In this way, they can represent enormous savings, since they would activate any element only when they detect our presence, and deactivate it automatically.

Read next: Best bedroom hidden cameras | Best Spy Camera Watch | Best low level CO detector | Best Wifi Router EMF Protection | Best Camera for MEVO Plus | Best Security Camera Without Subscription | Best Budget Camera for Blue Iris | Best Barking Dog Alarms | Best Free VPN for Rainbet | Best Solar Powered Security Camera | Alarmes Maison