Kestrel 4250 (Racing) - Manual (Page 7)

Kestrel ® 4250 Racing Weather ® Tracker
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BARO screen, since the pressure changes will be due to changes in elevation far more than to changes in the
weather.
In general, changes in barometric pressure associated with weather changes are small over the course of one
day, but they will affect the accuracy of the altimeter over time. This is why aircraft reset their altimeters at
every airfield by entering the field’s “altimeter setting” or reference pressure. Accordingly, if accurate altitude
readings are your primary interest, you should reset the reference pressure on your Kestrel Meter regularly.
If you encounter an elevation landmark, you can adjust the reference pressure until the altitude matches the
landmark elevation. This will correct the altitude for any pressure changes due to the weather. (Or, you can
obtain an updated reference pressure from the sources described above.)
The above discussion applies to ALL pressure altimeters, including one you may have in a watch or other
device, but not to GPS altimeters, which use satellite triangulation to determine altitude. Note that with
present GPS technology, pressure altimeters remain more accurate for measuring altitude change.
This is why airplanes still rely on pressure altimeters, not GPS.
Finally, the DENSITY ALTITUDE screen is calculated from the absolute values of station pressure,
relative humidity and temperature, and is not affected by the reference values entered in the BARO and
ALTITUDE screens.
MAIN SETUP MENU
You can customize your Kestrel Meter in multiple ways. Press the button to access the Main Setup Menu.
Press the button to select the highlighted setting. The Main Setup Menu contains: OFF, Memory Options,
Measurements, Graph Scale, Units, User Screens, System, Date & Time, Language and Restore.
Off
Press the then the button to turn the display off. Even when the Kestrel Meter’s display is turned
off, the unit will continue to automatically store data at the defined Store Rate. The battery life will be
decreased if data is stored frequently. The only way to completely shut off the unit is to remove the
batteries. Custom settings and data will be stored when the batteries are removed.
Memory Options
These settings control the data storage properties.
Setting Description Operation
Clear Log
(Go/Done) All stored data is cleared. This will also clear
Min/Max/Avg data.
Press or to clear the log.
Reset MMA
(Go/Done) All Min/Max/Avg data is cleared. Chart data
will remain intact.
Press or to clear the MMA.
Auto Store
(On/Off) When On, data is automatically stored at
preset Store Rate. When Off, data is only
stored when manually captured with the
button.
Press or to toggle between
On and Off.
Store Rate
(2 sec. – 12 hr) The frequency at which data sets are
automatically stored. (Battery life may be
shortened if data is stored frequently.)
Press or to increase or
decrease Store Rate frequency.