Garmin gpsmap 192c Manuale Utente

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GPSMAP 192C Owner’s Manual 
71
M
AIN
 M
ENU
 > 
U
NITS
 T
AB
•   Heading—selects the reference used in calculating heading 
information. You can select from Auto Mag Var, True, Grid, 
and User Mag Var. Auto Mag Var provides magnetic north 
heading references that are automatically determined from 
your current location. True provides headings based on a 
true north reference. Grid provides headings based on a grid 
north reference (and is used in conjunction with the grid 
position formats described on page 
70
). User Mag Var allows 
you to specify the magnetic variation at your current location 
and provides magnetic north heading references based upon 
the variation you enter.
To enter a user defined magnetic variation:
1.   With the 
Heading field set to User Mag Var, highlight the 
heading reference field (immediately to the right), and press 
ENTER
2.   Use the 
ROCKER to enter the magnetic variation at your 
current location, and press 
ENTER.
  WARNING: If User Mag Var is selected, you must periodically 
update the magnetic variation as your location changes. Using 
this setting, the unit does not automatically calculate and 
update the magnetic variation at your present location. Failure 
to update this setting can result in substantial differences 
between the information displayed on your unit and external 
references, such as a magnetic compass.
Manually enter a 
magnetic variation.
•   Distance, Speed and Elevation—select the units of measure 
for distance, speed, and elevation readouts in Nautical  
(nm, kt, m), Statute (mi, mh, ft), or Metric (km, kh, m) terms.
•   Depth—select units of measurement for depth in Feet (ft),  
Fathoms (fa) or Meters (m).
•   Temperature—select the units of measure for temperature 
in Fahrenheit (°F) or Celsius (°C).