In 1800, Sir William Herchel was credited with the discovery of the infrared spectrum.
By placing a thermometer in a prism of light, he was able to measure the temperature
difference between the rainbow of different colors. A higher temperature was recorded
when he moved the thermometer past the red portion of the prism into a dark area.
This was the beginning of the investigation into the infrared spectrum.
After further investigation, we now know that infrared radiation is a form of electromagnetic
radiation, which has a longer wavelength than visible light. Both infrared radiation
and visible radiation travel at the speed of light, which provides both forms of
radiation the ability to be focused, reflected and refracted. Some other forms of
electromagnetic radiation include radio waves, ultraviolet waves and x-rays, just
to name a few. All objects emit infrared radiation when they are above zero degree
Kelvin. Infrared radiation is generated by the acceleration of charged particles.
A hotter particle will generate more infrared radiation, because of the increase
of molecular activity. The infrared camera does not detect heat, but rather the
thermal radiation that an object emits. Infrared radiation is measured in microns
or one millionth of a meter. The infrared camera measures wavelengths between 8
- 12 micrometers, which is longer than visible light, which measures between .4 -
.75 micrometers in the electromagnetic spectrum. When a metal object is heated up,
it typically will turn red to the visible eye. As the object begins to cool and
the red color begins to diminish, the infrared camera will still detect the molecular
activity that is occurring. This infrared technology is used today for many building