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UV Dose

The units generate a UV dosage of at least 30,000 microwatt-seconds per square centimeter (μW-s/cm2), even at the end-of-lamp life (EOL), which is more than sufficient to destroy most waterborne microorganisms, such as bacteria, yeasts, algae etc…..

Dosage is the product of Intensity & Time

Dosage = Intensity  x  Time

= microWatt/cm2  x  time

= microwatt-seconds per square centimeter (μW-s/cm2)

Note: 1000 μW-s/cm2 = 1 mJ/cm2 ( milli-Joule/cm2)

UV Transmission (transmittance) deals with the effectiveness in which the 2537 Angstrom units (254 nanometers, 254nm) wavelength of ultraviolet light is transmitted through the water. The higher the transparency of the water, the more effective the UV system becomes. This optical clarity is evaluated by performing a test which passes incident light through a 1 cm depth of water and recording this against the same test using distilled water as a reference. Distilled water will pass 100% of the incident light through a 1 cm depth.

As a general guideline, the following are some typical UV transmission rates (UVT):

City water supplies:                          85-98%

De-ionized or Reverse Osmosis water:        95-98%

Surface waters (lakes, rivers, etc):          70-90%

Ground water (wells):                       90-95%

Other liquids:                              1-99%