Ultraviolet (UV) light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV. It is named because the spectrum consists of electromagnetic waves with frequencies higher than those that humans identify as the colour violet.
Our eyes cannot see it – UV rays are harmful to our optic organs and are thus blocked before they reach the retina.The cornea at the front of the eye stops and absorbs UV rays. But if bombarded by the rays the corneas can be burned. Our eyes become fogged up, they are painful and we call it snow blindness.The eyes of reindeer in the Arctic, however, admit and register UV light all the way down to a wavelength of 320 nanometres.
“Using UV inks will result in an increase in productivity for printers and converters,” said Mr. Weissman. “Overall increase in productivity is one reason that UV technology has seen strong growth rates. If you look at markets where UV dominates, it is because of significant productivity increases. In the screen market, printing tends to be a slow, long process that requires a lot of drying time. There is no way to print on a CD without using UV inks.”
Ozone generation using ultraviolet light has been used for many years for many industrial applications. Ozone is a powerful oxidising agent, second among elements only to fluorine. It can oxidise many organic compounds and is used commercially as a bleach for waxes, oils, and textiles, and as a deodorising agent.
Ultraviolet UV disinfection has many advantages over alternative methods. Unlike chemical biocides, Ultraviolet UV disnfection and sterilisation techniques do not introduce toxins or residues into process water and does not alter the chemical composition, taste, odour or pH of the fluid being treated. This is one of the most important aspects of all ultraviolet treatment systems. This feature is especially important in the food and dairy industry where the chemical dosing of incoming process water can compromise flavours and changes the physical chemical properties of the food products.
Starting this year, Best Western housekeepers will be equipped with ultraviolet sterilization wands to use on highly touched areas such as telephones, bathroom fixtures and light switches. UV black lights will be used during housekeeping inspections to detect biological matter and other particles, the chain said.
UV light makes many organic compounds fluoresce. Art dealers use UV lights to check if art has been touched up, since older paints have a lot of organic compounds and modern paints have relatively little. On ancient Greek statues, tiny fragments of pigment still left on the surface glow bright, illuminating more detailed patterns.
Ultraviolet Germicidal Irradiation - UVGI - is a common tool in laboratories and health care facilities and is becoming more and more popular with the general public and HVAC engineers. Interest in UVGI is increasing with the growing pandemic concerns and the opportunity to use germicidal UV for reducing energy and maintenance costs. Previous applications of UVGI have focused mainly on control of tuberculosis transmission, but a wide range of airborne respiratory pathogens are susceptible to deactivation by UVGI.
Anthrax can be reduced with the use of ultraviolet 254 lamps and fixtures. In fact, when used correctly, these UVC fixtures will reduce up to 99% of airborne mold, bacteria and other microorganisms including Anthrax spores*.
Most of us are exposed to large amounts of UVA throughout our lifetime. UVA rays account for up to 95 percent of the UV radiation reaching the Earth's surface. Although they are less intense than UVB, UVA rays are 30 to 50 times more prevalent. They are present with relatively equal intensity during all daylight hours throughout the year, and can penetrate clouds and glass.
Ultraviolet radiation is composed of three wavelengths: UVA, UVB and UVC. While UVC isn't a concern for skin cancer, UVA and UVB play different roles when it comes to tanning, burning, and photoaging.