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Every GyroTrac sensor is calibrated at the factory
for a perfect-world environment. However, hard
and soft iron effects on your vessel can distort the
magnetic field around the sensor, causing errors
in its reported heading. To compensate for these
magnetic distortions, follow these steps to
calibrate the sensor.
NOTE: If you are not installing the GyroTrac sensor
for the first time, you will need to clear the calibration
score first (see Appendix F on page 44).
Run the Autocalibration Function
The system’s Autocalibration function is set to
“On” at the factory. This function allows the
sensor to calibrate itself automatically when you
steer the vessel through two circles.
a. Select a calm day and navigate the vessel to a
clear area. Excessive pitching and rolling can
distort calibration data.
b. Apply power to the TracVision system.
c. Just before you begin, note the vessel’s
heading.
d. Steer the vessel at a slow, steady speed
through two full circles that take at least two
minutes each to complete (see Figure 43). Use
the heading you noted in Step c to confirm
when you have completed each full circle.
TIP: Try to time your turns so that it takes
approximately 30 seconds to turn 90º. Each circle does
not have to be completely round, but make sure you
turn a full 360º for each.
Check the Calibration Score
Once you have completed the two circles, follow
these steps to check the calibration “score.”
a. Press the center MENU button on the ADCU
to access the onscreen menu (see Figure 44).
b. At “Setup display type?”, press NEXT until
the display shows “Control compass?” Then
press ENTER and press YES to confirm.
30 Seconds
1 Minute
1 Minute,
30 Seconds
2 Minutes
Cir
cle
#
1
Cir
cle
#
2
Figure 43: Running Autocalibration
Setup display type?
Enter Next Return
Control compass?
Enter Next Return
Menu
Set AutoCal On/Off?
Yes
Next
Return
Read Cal score?
Yes
Next
Return
Until “Control compass” shown
Until “Read cal score” shown
At “ARE YOU SURE?,” press YES
Figure 44: Viewing the Calibration Score on the ADCU
Calibrate the Sensor
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