Kestrel 4200 (HVAC) - Manual (Page 13)

Kestrel ® 4200 Pocket Air Flow ® Tracker 25
Relative Humidity
The amount of water vapor actually in the air divided by the maximum amount of water vapor the air could
hold at that temperature, expressed as a percentage.
Station Pressure
The air pressure of your location, NOT reduced to the sea level equivalent.
Temperature
The ambient air temperature.
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.
DEFAULT SETTINGS
UNIT METRIC IMPERIAL
Wind Functions M/s mph
Temperature Functions °C °F
Barometric Pressure hPa inHg
Altitude Functions M Ft
Time Format 24 hour 12 hour
Date Format Day/month/year Month/day/year
SETTING FACTORY DEFAULT
Automatic Data Store On
Data Store Rate 1 hour
Data Overwrite On
Manual Data Store On
User Screen 1 Air velocity, air flow, temperature
User Screen 2 Humidity, humidity ratio, wet bulb
User Screen 3 Air flow, temperature, humidity ratio
Display Contrast 10
Automatic Shutdown 15 minutes
Language English
PC Upload
Stored data may be uploaded to a PC with the optional Kestrel Interface.