How do motion sensing lights and burglar alarms work?

Author: External Author | | Categories: Home Security System , Residential Security System , Smart Home System

The "motion sensing" feature on most lights (and security systems) is a passive system that detects infrared energy. These sensors are therefore known as PIR (passive infrared) detectors or pyroelectric sensors. In order to make a sensor that can detect a human being, you need to make the sensor sensitive to the temperature of a human body. Humans, having a skin temperature of about 93 degrees F, radiate infrared energy with a wavelength between 9 and 10 micrometers. Therefore, the sensors are typically sensitive in the range of 8 to 12 micrometers.

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Original Article Source Credits: How Stuff Works,

Article Written By: NA

Original Article Posted on: NA

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