4.12 Infrared radiation detection u Infrared radiation, also known as infrared light, is the invisible light outside the red light within the suns light spectrum. Any object, when its temperature is higher than the absolute zero grade (i. e. -273.16C), is said to be in athermal status". The molecules and atoms of a substance in thermal status are in a continuous movement and rotation and an electron transition occurs to produce electromagnetic waves❑ 4.12 Infrared radiation detection Infrared radiation, also known as infrared light, is the invisible light outside the red light within the sun’s light spectrum. Any object, when its temperature is higher than the absolute zero grade (i.e. − 273 .16C ), is said to be in a “thermal status”. The molecules and atoms of a substance in thermal status are in a continuous movement and rotation, and an electron transition occurs to produce electromagnetic waves