DAVIS Sensor - UV for GroWeather or EnviroMonitor - Manual

Product # 7841, 7843, 6490
U V S
E N S O R
F O R S T A N D A R D ,
I N D U S T R I A L , & V A N T A G E
P R O W E A T H E R S T A T I O N S
The UV Sensor is a precision instrument that detects ultraviolet (UV) radiation
at wavelengths of 290 to 390 nanometers. The spectral response is closely
matched to the Erythema Action Spectrum, defined by McKinlay and Diffey
(1987) and internationally recognized as the radiation that is most responsible
for causing redness of the human skin.
Avoid touching the small white diffuser at the top of the sensor. Any skin oil
on this surface will degrade the sensitivity of the sensor. To remove any oil
present, clean the diffuser with a clean swab and ethyl (denatured) alcohol. Do
NOT use rubbing alcohol.
Note: It should be noted that sunburn is not the only consequence of exposure to UV radiation. Skin cancers,
cataracts, and damage to the immune system are caused by UV. Exposure to UV should be minimized.
The sensor is made up of the following components:
✦ Shield
The outer shell shields the sensor body from thermal radiation and pro-
vides 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.
✦ Body, housing the following components:
✦ Cap
Retains the diffuser and filter
✦ Diffuser
Provides (with gasket) a weather-tight seal and excellent cosine response.
✦ Filter
With multiple hard-oxide coatings, the filter provides the Erythema
Action spectral response. It is stable in the presence of heat and humidity.
✦ Detector
The semiconductor diode, with the filter, responds only to radiation in the
region of interest.
✦ Amplifier
Converts the detector current into a 0 to +2.5V signal.
✦ Cable
The standard version of the sensor includes an attached standard 40'
(12 m) cable. The industrial version includes a 16' (5 m) shielded cable.
The Vantage Pro version includes a standard 3' (0.9 m) cable.