DAVIS Vantage Pro Console - Manual (Page 49)

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Refer to this appendix to learn more about the weather variables that are
measured, displayed, and logged by your Vantage Pro Station.
Note: Some weather variables require optional sensors. See “Optional Sensors” starting on page 2.
Wind
The anemometer measures wind speed and direction, and is part of the Inte-
grated Sensor Suite (ISS). The console also 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 sen-
sors are available for wireless stations and can be used to measure up to
eight locations.
Apparent Temperatures
Vantage Pro 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 percep-
tion 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 protec-
tion from cooler air molecules. However, wind sweeps that comfy warm air
surrounding the body away. The faster the wind blows, the faster heat is car-
ried away and the colder you feel.
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 tempera-
ture 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