A Passive Infrared (PIR) Sensor is an electronic sensor to measure infrared light radiating from objects in its field of view. They are mostly often used in PIR-based motion detectors. PIR is made of a pyroelectric infrared sensor to detect the levels of infrared radiation and used as an electronic device to measure the infrared light radiating from objects or human bodies nearby to detect whether a human has moved in or out of the sensor range.
The PIR alarm does not radiate energy to space but depends on receiving infrared radiation from a warm body to create an alarm. When a warm body infrared radiation is irradiated on the detector directly, it will cause a temperature change effect to output a signal, but the detection distance will not be far. As to strengthen the detection distance of the detector, an optical system needs to add for collecting the infrared radiation, normally using a plastic optical reflection system for it.
This sensor is being commonly found in an appliance and gadget in home and business. PIR sensors are commonly applied in security alarms, automatically device or lighting applications.
THE ADVANTAGES :
．Small size sensor
．Wide lens range
．Delay time adjustable
．Provide security by detecting suspicious movement
．Easy to install and interface with motion sensor