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Specifications
Sensor (for both lamps and sun)
Silicon Carbide (SiC) Photodiode packaged on gold plated header via gold wire bonding under UV glass window cap, hermetically sealed. Filter: Metal Oxide Eeff (erythemally effective) and teflon diffuser inside UV glass cap.
Radiometer
Peak sunlight
response bandwidth:
290-298 nm
Total solar response:
290-400nm, Diffey
Display:
3 ½ digit LCD
Resolution:
0.1 UVI
Power Source:
9V DC battery
Accuracy:
±10% ref NIST
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Proper usage of Solarmeter Ultraviolet Radiometer
for Outdoor UV Index Measurement
The instrumentation used to
measure UV index for the U.S. E.P.A./NWS program
is directed toward the sky in a global normal
(perpendicular to level ground) inclination.
Therefore the Solarmeter® Model 6.5 is designed
to operate in the same fashion. Solar irradiance
measured this way includes direct (reduced by
cosine law depending on solar zenith angle)
plus diffuse (diffused by the atmosphere).
This vertical (global) reading represents an
average intensity value your body will experience
while being active on a tennis or volleyball
court, or lying flat on a blanket on the grass.
If however, you are reclined in a lounge chair
facing the sun perpendicular to the sun angle,
you will experience a higher UV intensity, as
represented by pointing the Solarmeter ®
directly at the sun. This value will typically
exceed the actual UV index number.
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UVI Meter
Spectral Response
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Blue
Line: Meter response
Black Line:
Erythemal response |
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Interpretation
of UV index Relative to Proper Precautions
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Skin
type |
Typical
Features |
Tanning
ability |
I |
Pale white
skin, blue/hazel eyes, blond/red
hair |
Always
burns, does not tan |
II |
Fair skin,
blue eyes |
Burns easily,
tans poorly |
III
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Darker
white skin |
Tans after
initial burn |
IV
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Light brown
skin |
Burns minimally,
tans easily |
V
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Brown skin
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Rarely
burns, tans darkly easily |
VI
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Dark brown
or black skin |
Never burns,
always tans darkly |
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For Type II untanned skin the time to beginning
of sunburn, one minimal erythemal dose (MED)
at 210 J/m² per MED, can be calculated
from the UV Index reading as follows:
Divide the UVI by 2.33 to get MED/hr. Then
divide MED/hr into 60 minutes.
Example for an 8.5 UVI reading: 8.5 / 2.33
= 3.65 MED/hr. Then 60 / 3.65 = 16.4 minutes.
Since minutes to burn for previously unexposed
Types I and II are so short, these types should
heed all of the following precautions even
at moderate UV index levels.
Precautions
Outdoors
To reduce the risk of sunburn, skin cancer,
and eye damage:
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Minimize sun exposure
at midday (10:00 a.m. to 4:00 p.m.)
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Apply sunscreen with
SPF-15 or higher to all exposed areas of
the body.
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Reapply sunscreen every
two hours, even on cloudy days, especially
after swimming or perspiring.
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Be aware of reflective
surfaces (water, sand, snow) which increase
UV exposure.
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Wear clothing that covers
the body and shades the face.
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Protect children by
keeping them from excessive sun and applying
sunscreen frequently to children older than
6 months of age.
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Wear sunglasses that
absorb 99-100% of the full UV spectrum when
outdoors in bright sun.
Remember, the most important UV damage prevention
is to avoid sunburn.
The Solarmeter® Model 6.5 is not a medical
instrument, but rather an affordable scientific
instrument designed to help you avoid sunburn
by providing an instantaneous UV index value.
Among the outdoor variables affecting
UV intensity are:
- Seasonality/Sun Zenith Angle
- Location/Latitude/Geography
- Reflective Surroundings
- Altitude
- Weather conditions
- Ozone Layer Thickness
By regularly using the Solarmeter® you will
become very informed of damaging UV levels in
many and varied conditions. This knowledge,
along with following the outdoor precautions
mentioned above, should help enable you to avoid
sun damage.
Note:Battery
operation voltage is 9V down to 6.5V. Below
6.5V the LCD numbers will begin to dim, indicating
the need for battery replacement. Under "typical"
service load, the battery should last about
2 years.
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