Encyclopedia of Electronic Components Volume 3

Chapter 4. passive infrared sensor

spatial

presence

passive infrared

In coloquial speech, the term motion sensor is usually understood to mean a passive infrared motion sensor.

The acronym PIR is often used for a passive infrared sensor. It is always capitalized, without periods.

Object presence sensors and proximity sensors require an active source of a magnetic field, ultrasound, or infrared radiation. A passive infrared sensor does not require any such source, and responds passively to heat radiated from the object that is being detected.

Other related components

• object presence sensor (see Chapter 3)

• proximity sensor (see Chapter 5)

What It Does

A passive infrared motion sensor, often described as a PIR, detects black-body radiation ...