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Tip
Use the SD card reader method to quickly transfer large
maps. Send maps your use frequently to the device’s internal
memory so you always have them when you need them.
Compass and Altimeter
PN-40 only
The PN-40 comes equipped with two sensors; an
electronic compass and a barometric altimeter.
The electronic compass works when the PN-40 is
stationary or moving at less than 1.5 miles per hour.
The compass readings calculated from GPS information
are accurate only when the device is moving.
The barometric altimeter uses the elevation adjusted
to mean sea level and barometric pressure to provide
more accurate elevation readings than the calculated
GPS elevation provides.
Changes in weather patterns and geographic locations
can cause errors in sensor readings. Calibrating the
sensors ensures that they record and display accurate data
on the device and record accurate data in the track file.
The Calibrate option is available from the Satellite Page and
the Compass Page, and is under the Compass & Altimeter
option on the Device Setup Page.
In addition, from the Device Setup > Compass & Altimeter
menu, you can enable or disable the electronic compass,
barometric altimeter, and the auto-calibrate barometer
options, or restore the default settings.
Compass Calibration
Calibrate the electronic compass the first time
you use the PN-40.
Make sure you are outside and away from magnetic
fields, such as those caused by vehicles and power
lines, when you calibrate the compass.
Calibrate when you change the batteries—batteries,
even of the same type, have unique magnetic fields
that affect the accuracy of the electronic compass.
The device periodically checks the compass
accuracy; if it is poor, “Poor Accuracy” appears in the
bottom right corner of the Compass Page and a red
exclamation point displays in the Heading info field.
If the warning does not go away, try calibrating
the compass.
Additional Information