Product specifications

DS6490 (Rev. F, 1/3/07)
2-21
Vantage Pro2
TM
Accessories
6490
UV Sensor
The UV Sensor measures the sunburning portion of the UV spectrum. Its
spectral response matches very closely the Erythema Action Spectrum
(EAS), defined by McKinlay and Diffey (1987) and adopted by the
Commission Internationale de l’Eclairage (C.I.E.) as the standard
representation of the human skin’s sensitivity to UV radiation. The sensor measures global solar UV irradiance, the
sum of the components of solar UV transmitted directly and those scattered in the atmosphere. Scattered UV is a major
portion of global irradiance.
The transducer is a semiconductor photodiode that responds only to radiation in the region of interest. The diffuser
provides an excellent cosine response. With multiple hard-oxide coatings, the interference filter provides the
Erythema Action spectral response. It is stable in the presence of heat and humidity. The outer shell shields the sensor
from thermal radiation and provides a path for convection cooling of the body, minimizing heating of the sensor
interior. It provides a cutoff ring for cosine response, a level indicator, and fins to aid in aligning the sensor with the
sun’s rays. Spring-loaded mounting screws, in conjunction with the level indicator, enable rapid and accurate
levelling of the sensor. Each sensor is calibrated against a Yankee Environmental Systems’ Ultraviolet
Pyranometer, model UVB-1, in natural summer daylight.
The UV Sensor is optional on Vantage Pro2 weather stations. It is standard on the Vantage Pro2 Plus.
Please refer to the WeatherLink
®
for Vantage Pro
®
and Vantage Pro2
™
specification sheet for optional data logging
and charting capabilities available for this product.
General
Operating Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . -40° to +150° F (-40° to +65° C)
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . -50° to +158°F (-45° to +70°C)
Transducer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Semiconductor photodiode
Spectral Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280 to 360 nm (Erythema Action Spectrum)
Cosine Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±4% of reading (0° to 65° incident angle); ±9% of reading (65° to 85°
incident angle)
Supplied Cable Length . . . . . . . . . . . . . . . . . . . . . . . . . . 3' (0.9 m)
Cable Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-conductor, 26 AWG
Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Modular RJ-11
I/O Specs
Green wire. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Output (0 to 2.5VDC); 150 mV per UV Index, 364 mV per MED/hour
Black & Red wires . . . . . . . . . . . . . . . . . . . . . . . . . . Ground
Yellow wire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +3V ±10%, 2.4 mA
Housing Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UV-resistant ABS plastic
Dimensions (length x width x height) . . . . . . . . . . . . . . . . 2” x 2.75” x 2.25” (51 mm x 70 mm x 57 mm)
Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 lbs. (226 g)
Sensor Output
Ultra Violet (UV) Radiation Dose
Resolution and Units . . . . . . . . . . . . . . . . . . . . . . . . 0.1 MEDs to 19.9 MEDs; 1 MED above 19.9 MEDS
Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 199 MEDs
Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±5% of daily total
Drift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . up to ±2% per year
Update Interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 seconds to 1 minute (5 minutes when dark)
Ultra Violet (UV) Radiation Index
Resolution and Units . . . . . . . . . . . . . . . . . . . . . . . . 0.1 Index
Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 16 Index
Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±5% of full scale (Reference: Yankee UVB-1 at UV Index of 10
[extremely high]) plus 0.5 UV Index per 100' (30 m) of additional cable