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Station Pressure
The air pressure of your location, NOT reduced to the sea level equivalent.
Temperature
The ambient air temperature.
True North
True north is a navigational term referring to the direction of the North Pole relative to the navigator’s
position. The direction of true north is marked in the skies by the celestial north pole.
Wet Bulb Temperature
The lowest temperature to which a thermometer can be cooled by evaporating water into the air
at constant pressure. This measurement is a holdover from the use of an instrument called a sling
psychrometer. To measure wet bulb temperature with a sling psychrometer, a thermometer with a wet
cloth covering over the bulb is spun rapidly through the air. If the relative humidity is high, there will be
little evaporative cooling and the wet bulb temperature will be quite close to the ambient temperature.
Some exercise physiology guides use wet bulb temperature, rather than heat index, as a measure of the
safety of exercise in hot and humid conditions.
Wind Chill
The cooling effect of combining wind and temperature. The wind chill gives a more accurate reading
of how cold it really feels to the human body. The Kestrel Meter’s wind chill is based on the National
Weather Service standards as of November 1, 2001.
