The seven colors of a rainbow from red to violet are the spectrum of visible light. But the visible spectrum is only a small part of the entire electromagnetic spectrum. Extending out from the red edge of the visible spectrum is a type of invisible radiant energy called infrared (heat ray) radiation. It has longer wavelengths than visible light, and the property of heating up objects irradiated by it. It is subdivided into wavelength regions called near-infrared, mid-wavelength infrared and far-infrared, each named for its relative proximity to the visible spectrum.
Near-infrared is the region used for temperature rise testing done for new material research. Far-infrared is used for imaging, cooking and heating applications.
Thermo Riko’s infrared heating systems use infrared in the near-infrared region with wavelengths of between 700 and 3,000 nm.