ABSTRACT
Gamma rays, x-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves are electromagnetic radiation waves. The only difference among these different types of radiation is wavelength or frequency range. In order, wavelength increases from gamma rays, x-rays, ultraviolet, visible, infrared, and microwaves to radio waves. Table 7.1 shows that the energy level declines as wavelength increases. Infrared (IR) wavelengths range from 0.78 µm to 1000 µm, where 1 µm equals to 10−6 m (commonly referred to as 1 micron). Infrared detectors use a chemical’s IR radiation absorption characteristics to detect and identify it.
