IR SENSOR (Infrared)

ISI certified IR sensor (Infrared)

An IR SENSOR (Infrared) is an electronic device that measures and detects infrared radiation in its surrounding environment. Infrared radiation was accidentally discovered by an astronomer named William Herchel in 1800.

There are two types of infrared sensors: active and passive. Active infrared sensors both emit and detect infrared radiation. Active IR sensors have two parts: a light emitting diode (LED) and a receiver.

Passive infrared (PIR) sensors only detect infrared radiation and do not emit it from an LED. Passive infrared sensors are comprised of:

• Two strips of pyroelectric material (a pyroelectric sensor)
• An infrared filter (that blocks out all other wavelengths of light)
• A fresnel lens (which collects light from many angles into a single point)
• A housing unit (to protect the sensor from other environmental variables, such as humidity)