DAVIS Weather Envoy (6316, 6316C) - Manual (Page 28)

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UV Dose and Sunburn - Use this plot to estimate the MED dose leading to sunburn. A
person with Type II (Environment Canada) skin type might choose 0.75 MED as the
maximum for the day; in contrast, a person with Type V (Environment Canada) Skin Type
might consider 2.5 MEDs a reasonable dose for the day. NOTE: the Weather Envoy
assumes a Fitzpatrick (Environment Canada) Skin Type of II.
UV Index
Weather Envoy can also record UV Index, an intensity measurement first
defined by Environment Canada and since been adopted by the World
Meteorological Organization. UV Index assigns a number between 0 and 16
to the current UV intensity. The US EPA categorizes the Index values as
shown below. The lower the number, the lower the danger of sunburn. The
Index value published by the U.S. National Weather Service is a forecast of
the next day’s noontime UV intensity. The Index value displayed in Weath-
erLink is the result of a real-time measurement.
T ABLE A-3: UV I NDEX
Index
Values
Exposure
Category
0 - 2 Minimal
3 - 4 Low
5 - 6 Moderate
7 - 9 High
10+ Very High
UV Dose that Causes Sunburn
All Burn
Some Burn
I
II
III
IV
V
VI
1
2
3
4
Skin T
ype (Environment Canada)
Skin Phototype (EP
A)
UV Dose (MEDs)
1 2 3 4 5 6
20 40 60 80 100 120 mJ/cm
2