About Ultraviolet and Infrared

The difference between ultraviolet and infrared is that ultraviolet has a greater frequency and a shorter wavelength. The wavelength of infrared is between 740 nanometres and 1000 nanometres while ultraviolet is between 10 nanometres and 4000 nanometres. The intervening wavelengths between 400 and 750 nanometers are visible light.


The light we see with our eyes is really a very small portion of what is called the "Electromagnetic Spectrum." The Electromagnetic Spectrum includes all types of radiation - from the X-rays used at hospitals, to radio waves used for communication, as well as microwaves. Radiation in the Electromagnetic Spectrum is often categorized by wavelength. Short wavelength radiation is of the highest energy and can be very dangerous - Gamma, X-rays and ultraviolet are examples of short wavelength radiation. Ultraviolet light (UV) is an invisible light that is part of the sun's radiant spectrum. Applications – Curing, drying, sterilisation etc..


Longer wavelength radiation is of lower energy and is usually less harmful - examples include radio, microwaves and infrared. A rainbow shows the optical (visible) part of the Electromagnetic Spectrum and infrared (if you could see it) would be located just beyond the red side of the rainbow. Applications – Heating, drying, baking, cooking, melting etc..