UV light, also known as ultraviolet radiation or UV radiation, cannot be seen by humans, only felt. Probably the best known natural source of UV light is the sun. Artificially, UV radiation can be generated with the help of mercury vapor lamps and special light sources. UV light is divided into the three categories UV-A, UV-B and UV-C according to its wavelength. The short-wave UV-C light is largely absorbed by the ozone layer and thus does not reach our skin. The UV-B light makes it a little further, but is also rendered harmless by the cloud layers to 90%. UV-A light, on the other hand, is responsible for sunburn, eye damage, skin cancer and far more biological damage.
UV radiation can cause irreparable damage to sensitive works of art, especially works made of paper, such as prints, manuscripts or books. Depending on the duration and intensity of light, exposure starts biochemical processes that accelerate the organic aging process and lead to structural changes in paper, ink and paint. That is why we use only adjustable LED light units in our scanning systems for the most gentle illumination of the originals.
On the other hand, UV light (UV fluorescence) is used in the field of art science as an examination method, e.g. to make surface phenomena or faded inks on works of art, which cannot be perceived by the naked eye, visible by selective excitation with light of certain wavelengths. – In this context, we use UV light exclusively in our multispectral system.