Infrared motion sensors use the infrared light spectrum, a light that is invisible to the human eye. Infrared sensors (Passive InfraRed / PIR) compare the temperature of any object passing through the protected area with the background setting and/or measure the rate of change in an object’s temperature. Because of these features, apart from burglar alarms, these sensors are also used to detect fires or malfunctioning devices.
What are the other advantage of infrared sensors?
In terms of cost, infrared sensors are less expensive than ultrasonic sensors and microwave sensors. Also, they are usually smaller and more reliable than them. Since they do not react to sharp impacts, radio waves, or vibrations, the risk of false alarms is extremely low. That’s why they are part of home security systems that are often sold packaged.
In the meantime, I’d like to share a few links here, in case you’d like to check out other articles on our website: Sound Detection Systems, Acoustic Sensors, Microwave Sensors, and the Facebook page.
What is the disadvantage of infrared sensors?
The major disadvantage of infrared motion sensors is that they do not cover an entire room. More precisely, it perceives the room as slices or stripes, leaving undetected intermediate stripes between these stripes. A perceived area is a large number of linear areas, like fingers pointing at the room, we could say. Areas between fingers are not detected.
For this reason, many systems of infrared sensors come with a variety of lenses that allow the user to choose the type of security coverage they want for their zone of protection.
Nevertheless, infrared sensors that see the room to be protected in slices provide adequate protection in many cases. Because, for example, even if half of a door is not detected by the sensors, the motion in the detected section is sufficient for the warning. Or, even if there is a small window that is completely out of detection, the motion starting from that window will still be caught, as it will continue in the detected area.
You may need to get more up-to-date information about infrared sensors and home security systems in general. For this, the updated links of the companies you will see on the page can help you.