An important thing to know is that ultraviolet (UV) is not a single entity, but a wide band of wavelengths from approximately 100nm to 400nm. The chief natural source of UV is the sun. In fact, about 99% of all energy emitted by the sun is UV, most of which is in the region between 300-400nm. Artificial sources of UV include incandescent, gas discharge, low pressure mercury, medium pressure mercury metal halide, electrodeless and xenon lamps.
An interesting characteristic of UV radiation occurs when it falls upon certain substances known as phosphors, where it causes the phosphors to emit specific visible radiation. This phenomenon is known as fluorescence. A similar effect is phosphorescence but the emission lasts longer after the UV source is removed.
Scientifically speaking, ultraviolet light is electromagnetic radiation in the part of the spectrum between x-rays and visible light. It differs from light only in that its wavelengths are too short to be seen by the human eye. The boundary between visible light and UV light is usually taken to be radiation with a wavelength of 400 nanometers. Medical literature subdivides UV light into three ranges: UVA (alsao known as blacklight) is radiation 315nm and higher, UVB (midrange) is between 280-315nm and UVC (shortwave) is 280nm and lower.
Unlike x-rays, UV radiation has a low power of penetration, therefore the effects on the body are limited to skin and eyes. Direct and indirect exposure to UV, especially in the UVB and UVC range, include sunburn, aging and carcinogenic changes. UV protective eyewear, clothing and creams are recommended whenever exposure to UV is possible.
The unique properties of UV fluorescence and phosphorescence are part of the many phenomena that make ultraviolet radiation vital to science and industry alike. Many applications where UV radiation is used is shown below. Also refer to UVP's Application Bulletins for additional information.
Ultraviolet Spectrum
UV Applications
Longwave UV - 365nm • Laboratory/Research: Bacterial Identification • Specimen Staining • Gel Electrophoresis • Chlorination • Fluorochemistry • Pesticide Analysis • Fluorescence Photography • Titration Processes • TLC • Nucleic Acid Visualization • Genetic Experiments • Virology • Sanitation: Aflatoxin Detection • Rodent Contamination and Lice Detection • Detection of Food and Textile Contamination • Milkstone Inspection • E-Coli Water Testing • Culture Fluorescence • Medical: Medical Diagnosis • Dermatology • Cosmetology • Education: Fluorescence Demonstration and Analysis • Industrial: Non-Destructive Testing • UV Curing • Magnetic Particle Inspection • Inspection of Conformal Coatings • Leak Detection • Criminology: Detection of Altered Documents • Counterfeit Currency Detection • Signature Verification • Forensic Applications • Coding/Marking • Arson Investigation • Lab Testing • Electronics: Clean Room Inspection • Epoxy Coat Inspection • Miscellaneous: Examination of Fine Art • Archaeology • Entomology • Photoresist Exposure • Philately • Re-Admission Control • Mineralogy • Automotive: Leak Detection • Windshield Repair
Midrange UV - 302nm • Research: Gel Electrophoresis • Gel Viewing • Optical Lab Measurements • Industrial: UV Curing • Gradient Sampling • Solar Experimentation • Medical: Phototherapy • Dermatological • Miscellaneous: Mineralogy • Art and Museum Inspection
Shortwave UV - 254nm • Criminology: Document Examination • Field Clues • Arson Investigation • Toxicology • Education: Fluorescence Demonstration and Analysis • Laboratory/Research: Fluorochemistry • Mercury Detectors • Optical Alignment • Pesticide Analysis • Polymer Curing • Sterlization • DNA Analysis • Chromatography • Biochemical Testing • Electrophoresis • TLC • Mutation • Mycology • Nucleic Acid Visualization • Photochemistry • Photo Disassociation • Miscellaneous: Air Pollution • E-Coli Testing • Alumina Testing • Archaeology • Fluorescence Photography • Mineralogy • Philately
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Corporate Office: UVP, Inc. 2066 W. 11th Street, Upland, CA USA 91786 * Telephone: (800) 452-6788 or (909) 946-3197
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Telephone: +44(0)1223-420022 * Fax: +44(0)1223-420561 * E-Mail: uvp@uvp.co.uk
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