INFRARED (IR)

Electromagnetic radiation with wavelengths between visible red light and microwaves; it ranges from 750 to 1 million nanometers (1 millimeter). Infrared is subdivided into near (NIR, 750 to 2,500 nanometers), middle (MIR, 2,500 to 30,000 nanometers), and far (FIR, 30,000 to 1 million nanometers). [See also radiation].