Introduction to Infrared Technology
- Category: About Infrared Heat
Infrared radiation is a form of electromagnetic energy that is generated by the vibration and rotation of atoms and molecules within all objects with temperatures above absolute zero (0º Kelvin; -459º F; or -273º C). Electromagnetic energy, which travels at the speed of light (3.0 x 108 meters per second, or 186,000 miles per second), is comprised of waves that can be measured both electrically and magnetically. The Electromagnetic Spectrum categorizes the wavelengths of these electromagnetic waves.
Along the electromagnetic spectrum, wavelength increases and wave frequency decreases in the following progression: gamma rays (with very short wavelengths in the 10-5 micron range), x-rays, ultraviolet, visible light, infrared, microwaves, radio waves (with long wavelengths in the 1 kilometer range). Infrared (literally meaning "below" or "beyond" the red) is located between the visible and microwave portions of the electromagnetic spectrum and shares many of the same properties of visible light, except it has a longer wavelength.
When infrared waves encounter a solid object they can be reflected (bounce off), diffracted (scattered), refracted (bent), transmitted (pass through), or absorbed by the object - several of these effects can take place at the same time. The visible portion of the spectrum ranges in wavelength from 0.38 microns to 0.76 microns. The infrared portion, which is not visible to the human eye, begins at 0.76 microns and extends to 10.0 microns (micron = one thousandth of a millimeter, one millionth of a kilometer). All objects emit infrared as a function of their temperature.