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Appendix A
Weather Data
Refer to this appendix to learn more about the weather variables that are
measured, displayed, and logged by your Vantage Pro2 Station. Some weather
variables require optional sensors. See “Optional Sensors & Transmitting
Stations” starting on page 3.
Wind
The anemometer measures wind speed and direction, and is part of the Integrated
Sensor Suite (ISS). The console calculates a 10-minute average wind speed and
10-minute dominant wind direction. The 10-minute average wind speed is
displayed in the console ticker whenever wind has been selected on the console.
The last six 10-minute dominant wind directions are included in the compass
rose wind display.
Temperature
The ISS houses the outside temperature sensor in a vented and shielded
enclosure that minimizes the solar radiation induced temperature error. The
console houses the inside temperature sensor. Additional temperature sensors are
available for wireless stations and can measure up to eight locations.
Apparent Temperatures
Vantage Pro2 calculates three apparent temperature readings: Wind Chill, Heat
Index, and the Temperature/Humidity/Sun/Wind (THSW) Index. Apparent
temperatures use additional weather data to calculate what a human body
perceives the temperature to be in those conditions.
Wind chill
Wind chill takes into account how the speed of the wind affects our perception of
the air temperature. Our bodies warm the surrounding air molecules by
transferring heat from the skin. If there’s no air movement, this insulating layer
of warm air molecules stays next to the body and offers some protection from
cooler air molecules. However, wind sweeps that warm air surrounding the body
away. The faster the wind blows, the faster heat is carried away and the colder
you feel. Wind has a warming effect at higher temperatures.
Note:
Wind chill is not calculated above 92° F (33° C).
Heat Index
The Heat Index uses temperature and the relative humidity to determine how hot
the air actually “feels.” When humidity is low, the apparent temperature will be
lower than the air temperature, since perspiration evaporates rapidly to cool the
body. However, when humidity is high (
i.e.
, the air is more saturated with water
vapor) the apparent temperature “feels” higher than the actual air temperature,
because perspiration evaporates more slowly.
Summary of Contents for Vantage Pro2 Plus
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