Different Types of Motion Detectors

Motion Detectors can be classified into two types:- 1) Active and 2) Passive. Sub-divisionally, there are Proximity Detectors, Active Beam Motion Detectors and Passive Motion Detectors. Motion Detectors, as commonly known, detect motion in places like corridors, walkways, unmanned houses etc. They raise alarms when there is an intrusion and when there is any form of motion in the house. Lawns, and surrounding areas of homes can be monitored for any form of motion and those inside the house can be alerted on someone’s movement outside.

Active Motion Detectors

There are two types of Motion detectors in Active Motion Detectors. Both of them use infrared lights. They are simple technologies that we see in our everyday lives. The terms active and passive are determined by the way these Motion Detectors function. i.e., by sending or receiving. If the Motion Detectors function by sending out signals, they are called Active Motion Detectors. On the other hand, if they function by receiving, then they are called Passive Motion Detectors.

Active Proximity Motion Detectors

Here, the Motion Detector functions in an Active manner. The Motion Detector is actively involved in work than to be involved only during the time of action. The Motion Detector remains vigilant enough to function and raise alarms. These detectors send high frequency sound waves far above the decibels human ears can endure and this signal is sent back to the Motion Detector within a particular period of time. In some cases they use radar signals as well.

But if there is an intrusion, the signals hit the intruder and return quicker than normal. This sparks off an alarm from the detector. The detector immediately recognizes the quicker bouncing back of the signals and their reaching the detector in very little time. A very good example of this working principle is the automatic door, which slides open when someone comes closer to the doors.

Active Beam Motion Detectors

The mechanics of this motion detector is a far more simpler one. This is an active motion detector where the detector is constantly in work. From Automatic hand wash in restaurants and hotels to criss-cross invisible beams in libraries and other confidential premises. The detector sends out infrared light beams to a light detector and when the beam is intersected with by any object or humans, the detector recognizes it and raises an alarm.

This simple technology is the most commonly used of all the other motion detectors. Shops, restaurants, banks etc., use these kind of motion detectors.

Passive Motion Detectors

Passion Motion Detectors have no functioning of sending out signals unless and until confronted with. They use humans as a source to receive signals and function according to the magnitude of the signals received. This is because almost all the objects have a tendency of transmitting infrared lights and signals. The Passive Motion Detector can pick up signals from any other object.

Heat of the object determines the amount or frequency of the infrared light emitted. Though, the infrared light transmitted by the human beings is very low, passive motion detectors can pick them up through their light sensors and raise alarms. This makes us certain that there is some human element involved in the motion detector’s alarms.