Motion Detection Alarm

A motion sensor alarm is a device that uses optical, microwave, or acoustic sensor technologies to detect motion around your home or workspace; and to let you know that there is a physical security event that shouldn’t be happening. Motion sensors are also sometimes known as motion detectors.

Description

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.