Garmin 240 Fish Finder User Manual


 
27
Unit Operation
Setup Menu: Calibrations Tab
Calibrations Tab
The ‘Calibrt’ tab contains the ‘Keel Offset’ and ‘Water Type’ setups, and
a ‘Calibrate Speed’ function for use when a speed sensor is installed.
Keel Offset
The ‘Keel Offset’ fi eld allows the user to offset the depth reading for a
keel or for the draw on a larger vessel.
To set a Keel Offset:
1. Highlight the ‘Calibrt’ tab on the Setup Menu.
2. Highlight the ‘Keel Offset’ fi eld and press ENTER.
3. Use the Arrow Keys enter a new offset, then press ENTER to accept.
Water Type
Since sound waves travel through fresh and salt water at different rates,
it is necessary to select the ‘Water Type’ to ensure accurate depth readings.
To change the Water Type:
1. Highlight the ‘Calibrt’ tab on the Setup Menu.
2. Highlight the ‘Water Type’ selection fi eld and press ENTER.
3. Choose ‘Fresh’ or ‘Salt,’ then press ENTER to accept the selection.
Calibrate Speed
The ‘Calibrate Speed’ fi eld will be enabled when a speed sensor is
installed or when you are in simulator mode. This allows you to calibrate
the Fishfi nder speed to your boat’s speedometer or to your GPS speed.
To calibrate the Speed:
1. Highlight the ‘Calibrt’ tab on the Setup Menu.
2. Highlight the ‘Calibrate Speed’ button and press ENTER.
3. Run your boat, noting your top speed. Stop the boat and press ENTER.
4. With the speed fi eld highlighted, press ENTER and input your top
speed. Highlight ‘OK’ and press ENTER to fi nish the calibration.
Transducer at Surface
Enter (+) positive number to show
depth from bottom of keel
Transducer at Bottom of Keel
Enter (-) negative number to show
depth from surface
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