Safety and Qualuity
What is a Germicidal or UVGI Lamp?
Germicidal or Ultraviolet Germicidal Irradiation (UVGI) lamps are used
to: disinfect air and water; cure inks and coatings, disinfect foods
and destroy pollutants in water and air through UV-based "advanced
oxidation". UV energy can be effective in killing biological
contaminants such as mold/fungi, bacteria and viruses. For air
disinfection, lamps are typically placed inside air handling ducts,
mobile room air cleaning units and in special fixtures mounted toward
the ceiling in rooms. The most common applications are in hospital /
health care facilities, food processing plants, shelters, prisons, and
other commercial uses where it is important to eliminate biological
contaminants. The target wavelength for most ozone-free air
purification applications is 254 nanometers. For water purification,
ozone producing wavelengths are included and the target wavelength is
185 nanometers.
How does a Germicidal or UVGI Lamp Work?
Ultraviolet germicidal irradiation is produced by low-pressure mercury
lamps similar to fluorescent lamps without a phosphor and with a quartz
bulb. These lamps emit UV in the 200nm to 300nm range or that portion
of the UV spectrum called UV-C. Also known as "shortwave" UV, it
includes the target germicidal wavelength of 254nm. 95% of the relative
intensity occurs at the mercury discharge line of 254 nanometers -
proven to be the most effective in germicidal applications.
More on UVGI.
Ultraviolet rays have shorter wavelengths than visible light. A
wavelength, the distance between the crests of two waves, is often
measured in units called nanometers. A nanometer (nm) is a billionth of
a meter, or about 1/25,000,000 inch. Wavelengths of visible light range
from about 400 to 700 nm. Ultraviolet wavelengths range from about 1 to
400 nm and are beyond the range of visible light.
Ultraviolet technology is a non-chemical approach to disinfection. In
this method of disinfection, nothing is added which makes this process
simple, inexpensive and requires very low maintenance. Ultraviolet
purifiers utilize germicidal lamps that are designed and calculated to
produce a certain dosage of ultraviolet (usually at least 16,000
microwatt seconds per square centimeter but many units actually have a
much higher dosage.) The principle of design is based on a product of
time and intensity - you must have a certain amount of both for a
successful design.
Ultra Violet irradiation is an effective method of killing a broad
range of microbes. In essence, the UV radiation breaks the molecular
bonds in the organism's DNA. The most effective wavelength for
accomplishing this is 263nm; however, the very intense 254nm output
from low pressure Hg lamps is also very effective, as well as broader
spectral output from medium pressure UV lamps.
UV disinfects through a photochemical process. The contaminants that
pollute the indoor environment are almost entirely based upon organic
or carbon-based compounds. These compounds breakdown when exposed to
high intensity UV at 240 to 280 nm. Short-wave ultraviolet light can
destroy DNA in living microorganisms and breakdown organic material
found in indoor air. UVC effectiveness is directly related to intensity
and exposure time.
CAUTION:
Germicidal lamps emit UV which can be harmful. Caution notices are
provided in accordance with ANSI / IESNA RP-27.3-96 Recommended
Practice for Photobiological Safety for Lamps - Risk Group
Classification & Labeling. Germicidal lamps are in Risk Group 3
(High Risk). Avoid exposure to eyes and skin to unshielded lamp. Skin
or eye injury will result. Proper fixturing and operation is essential
for safe and effective application of this product.
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