noun
far-infrared rays; far-infrared radiation; FIR
Technical term for electromagnetic radiation with wavelengths longer than mid-infrared, commonly used in heating, spectroscopy, and astronomy.
遠赤外線は、暖房器具や調理器具に利用されている。
Far-infrared rays are used in heating and cooking appliances.
This telescope was designed to observe far-infrared radiation.