History of UVC Technology 1870 Studies on Batericidal
History of UV-C Technology 1870 • Studies on Batericidal Effects of Sunlight 1880 • UV Spectrum Identified as Primary Cause of Bactericidal Sunlight 1890 • First UV Lamps Developed 1903 • Niels Finsen awarded Nobel Prize For Research of UV Phototherapy 1908 • First UV Applications for Water Disinfection, Marseille, FR 1930 • Westinghouse Develops First Commercial UV-C Lamps 1940 • After WWII, Upper Room Air UV Systems Gain Popularity 1950 • UV Used Widely in Hospitals For Tuberculosis Control and Elimination 2000 • UV Systems Designed To Operate In Cool HVAC Environment Developed 2009 • UV Systems for Healthcare Area Disinfection Introduced
What is Ultraviolet Light? UV occurs naturally in sunlight UV-A (315 nm - 400 nm) Black lights and tanning lamps, harmful to eyes UV-B (280 nm - 315 nm) Causes sunburn and skin cancer UV-C (200 nm - 280 nm) Germicidal - Damages DNA in cells, optimum at 265 nm UV-C is naturally filtered by the ozone layer
How Does Ultraviolet Light Disinfect? n The Earth’s ozone layer filters UV-C which occurs naturally in sunlight n Germicidal UV-C systems artificially generate a wavelength of 254 nm which inactivates (disrupts DNA) of microorganisms including viruses, bacteria and mold . n Germicidal UV has been used safely in water, air and surface disinfection for many years
Construction of UV-C Lamps do not have the Fluorescent powder coating on the inside of the glass allowing the UV-C radiation outside of the lamp Fluorescent/Germicidal Lamp
Calculating Dosage DOSAGE = Intensity x Time Dosage is what determines effectiveness Example: 50 µw/cm 2 x 60 sec. (Time) x 60 min. x 24 Hours (Dosage) 4, 320, 000 µw/cm 2 (Intensity) } Tech Note: A Dosage of 330, 000 µw/cm 2 is required to “kill” Mold Aspergillus Niger A 18 watt Biax Germicidal Lamp has a UV irradiance of 51 µw/cm 2/sec
How It Works… n Any organic based cell exposed to UV-C Absorbs it at the molecular level. . . The organism is now destroyed & ineffective. It is unable to reproduce & unable to infect.
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