Advantages of motion sensor | Disadvantages of motion sensor

This page covers advantages and disadvantages of motion sensor (active and passive). It mentions motion sensor advantages and motion sensor disadvantages of both active and passive type.

Definition: The sensor device which detects motion is known as motion sensor. There are two types of motion sensors viz. active and passive. Active motion sensor transmits radio frequency towards the person/object and analyzes received frequency to determine the motion. The example of active motion sensor is microwave motion sensor.

Microwave Motion Sensor

Passive motion sensor senses heat and light to determine change in motion. The example is PIR sensor which receives change in thermal energy to determine the motion of object or person. PIR stands for Passive Infrared Sensor. PIR measures infrared light radiating from objects in its FOV (Field of View). By default it generates energy based on observed heat surrounding it. When human or any body comes nearby, it receives more thermal energy compare to normal condition. This way it determines presence or absence of the object or person.

PIR motion sensor

Refer Motion Sensor basics and types>> and Active vs Passive Motion Sensor>> for more information.

Advantages of motion sensor

Following are the advantages of motion sensor of active and passive types:
➨It can be used in very harse environment having irregular heat cycles (Active Motion Sensor).
➨It has more lifespan which is about 100000 Hrs (Active type).
➨It detects motion in light and dark conditions reliably in indoors. (Passive motion sensor)
➨It helps in providing security by detecting suspicious movement.
➨It is easy to install motion sensors.

Disadvantages of motion sensor

Following are the disadvantages of motion sensor of active and passive types:
➨Radio frequency at high power is harmful for humans (active type).
➨Radio frequency in microwave range do not penetrate metal objects (active type).
➨Passive motion sensors do not operate above temperature of 350C.
➨Passive sensor type works in LOS (Line of Sight) and does not work in non-LOS regions.
➨Passive type is insensitive to very slow motion of the object.
➨Passive Infrared (PIR) Sensor can detect human being within approx. 10 meters range.
➨Any kind of moving object can trigger the PIR sensor type.


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