How to determine the dose of UVC radiation needed to destroy a microorganism

To determine the radiation dose required to destroy a particular microorganism, it is important to know the actual UV-C radiation of the facility.

Different microorganisms have varying levels of susceptibility to germicidal radiation

Just like in nature, some plants or animals are more resistant than others. Some have a protective outer layer of protein or fat, or a stronger healing ability, and larger doses of UV-C radiation may be needed to destroy their nucleic acids.

The amount of energy required to kill a particular microorganism can be expressed as a UV-C dose . It is a time-dependent measurement, combining three parameters:

  1. UV-C Flux (or UV-C Power), measured in watts of UV-C radiation (W)
  2. Area irradiated, measured in square meters (m²)
  3. The irradiation time, measured in seconds (s)

The first two parameters can be combined to represent UV-C radiation (W/m²). In this case, the only other variable is the exposure time . The resulting UV-C dose measurement is expressed in watt-seconds per square meter (Ws/m²). Since the unit of energy, the joule, is equal to 1 watt per second, germicidal doses are often expressed in joules per square meter (J/m²).

To destroy different organisms , it does not matter whether the UV-C dose is the result of strong radiation for a short period , or that of weaker radiation for a longer period .

If a dose of 100 J/m² is necessary, it can be obtained in several ways , for example:

100W/m² x 1s = 100J/m²

10W/m² x 10s = 100J/m²

2W/m² x 50s = 100J/m²

Radiation dose for inactivation of microorganisms

Source: DT-Solution

What does Dose LOG 4 d/m2 mean:

Reflectors to increase UVC radiation

In addition to the high wattage (Joules) of our purifiers. They are all equipped with reflectors which multiply the power displayed.

Indeed, this makes it possible to capture the radiation at 360° and to concentrate it on the air in circulation.
This greatly amplifies UV-C radiation.

What are UVs?

These are electromagnetic waves that are invisible to the naked eye, they are also known as “black light”. UV rays have more or less long electromagnetic wavelengths but are always lower than that of light, which is what makes them invisible to the naked eye.

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