What we see is directly tied to how light refracts off objects, creating the color we perceive. While the color of a wavelength is an objective measurement, the colors we perceive are not. The perception of color is even different between species.
Sometimes we need a bit of help at seeing things that may not be highlighted or made visible through traditional wavelengths of light. A UV light does a great job at providing us with a visual insight into refraction that we don’t see from regular sunlight or lighting that falls outside of the extreme ends of the light spectrum.
You’re undoubtedly familiar with the term fluorescence, which is the word given to something that exhibits traits that cannot be seen with regular light. Fluorescent objects will require a UV light to ‘decode’ – and its uses range from simple fun to exploration and even security and forensics.
UV flashlights may be able to offer you a glimpse into a world usually hidden from sight. And best of all, they can be acquired for an affordable price and bring unique and useful functionality that you don’t find with other devices.
Before you can purchase the right UV flashlight, it is important to understand what nm is and how it affects the light you purchase. Nm is short for nanometers. Ultraviolet light, or ultraviolet radiation as it is also known, covers the range from 10nm’s to 400nm’s. It can be broken down into these specific segments:
You’ll notice the visible spectrum separated from the rest of the electromagnetic spectrum in the image above. UV light falls just to the left of the visible spectrum, with infrared on the right. Below, we can take a further look into the UV side of the spectrum in more detail.
Fluorescence is used to manufacture government documents and banknotes to help detect fraudulent copies or counterfeit cash. When you go to the bank, you may have seen that the teller will wave the notes under a light while processing them; the light being used is a UV light. There will typically be fluorescence within the security strip of bills that won’t be visible to the naked eye but will show clearly under UV light. Similarly, with documents like passports, fluorescent fibers embedded in them will become visible under UV light.
A UV flashlight, in turn, is a great way to scan over bank notes or documents to see whether or not they are legitimate. It is a useful tool for someone who wants to ensure that they are never in possession of counterfeit banknotes, something that happens now and then through currency circulation outside of the bank.
