what does infrared detector mean

An Infrared detector is a sensor used to detect infrared radiation. Infrared radiation refers to electromagnetic radiation with wavelengths other than visible light, and is often used in applications such as remotely measuring temperature or monitoring the movement of objects. An infrared detector usually includes an element that can sense infrared radiation, such as an infrared detector diode or an infrared thermal imager, and a signal processing circuit for converting the sensed infrared radiation into an electrical signal. Infrared detectors are widely used in industrial automation, temperature measurement, security monitoring, automotive assisted driving and other fields.