Appendix: Weather Data
Page 54
Vantage Pro Manual
Barometric Pressure
The weight of the air that makes up our atmosphere exerts a pressure on the
surface of the earth. This pressure is known as atmospheric pressure. Gener-
ally, the more air above an area, the higher the atmospheric pressure, this, in
turn, means that atmospheric pressure changes with altitude. For example,
atmospheric pressure is greater at sea-level than on a mountaintop. To compen-
sate for this difference and facilitate comparison between locations with differ-
ent altitudes, atmospheric pressure is generally adjusted to the equivalent sea-
level pressure. This adjusted pressure is known as barometric pressure. In real-
ity, the Vantage Pro measures atmospheric pressure. When you enter your loca-
tion’s altitude in Setup Mode, the Vantage Pro stores the necessary offset value
to consistently translate atmospheric pressure into barometric pressure.
Barometric pressure also changes with local weather conditions, making baro-
metric pressure an extremely important and useful weather forecasting tool.
High pressure zones are generally associated with fair weather while low pres-
sure zones are generally associated with poor weather. For forecasting pur-
poses, however, the absolute barometric pressure value is generally less
important than the change in barometric pressure. In general, rising pressure
indicates improving weather conditions while falling pressure indicates deteri-
orating weather conditions.
Note:
The following variables require optional sensors. See “Optional Sensors” starting on page 8.
Solar Radiation
What we call “current solar radiation” is technically known as Global Solar
Radiation, a measure of the intensity of the sun’s radiation reaching a horizon-
tal surface. This irradiance includes both the direct component from the sun
and the reflected component from the rest of the sky. The solar radiation read-
ing gives a measure of the amount of solar radiation hitting the solar radiation
sensor at any given time, expressed in Watts /sq. m (W/m
2
).
Note:
The Vantage Pro measures energy received in the spectral band between 400 and 1100 nm.
Summary of Contents for and Vantage Pro
Page 6: ...Page 6 Vantage Pro Console Manual ...
Page 10: ...Welcome to Vantage Pro Page 10 Vantage Pro Console Manual ...
Page 16: ...Console Installation Page 16 Vantage Pro Manual ...
Page 18: ...Console Installation Page 18 Vantage Pro Manual ...
Page 44: ...Using the Console Page 44 Vantage Pro Console Manual ...
Page 63: ...Vantage Pro Manual Page 63 ...