Furuno CI-35H - Manual (Page 9)

vii
[READ THIS FIRST!!]
IMPORTANT NOTICE ON TIDE MEASUREMENTS
(In nav-aided mode, tide accuracy depends heavily on gyro accuracy.)
SETTING SHIP’S HEADING
The CI-35/35H has the nav-aided mode to measure absolute tides even in deep waters where ground
tracking is unattainable. To achieve reliable measurements, however, you must supply accurate
heading (gyro) information and ship’s position (or speed/course) data to the CI-35/35H.
If you are going to use nav-aided mode, set the reading of the AD converter (gyro interface) exactly
with that of master gyrocompass.
Procedure
1. Confirm that the gyrocompass has settled and all the necessary compensations (latitude com-
pensation, weather compensation, etc.) are made correctly.
2. Manipulate the AD converter to obtain the same reading as you read on the master gyrocom-
pass. (Do not make adjustment while the ship is turning.)
If the gyro reading is accurate enough, the CI-35/35H should provide accurate tide information. If
the gyro data contains some error, however, you may see the following symptoms.
¡ Set/drift information on nav-aided mode differs from that on ground-tracking mode.
¡ Tide/tide differential information on nav-aided mode differs from that on ground-tracking
mode.
0
10
20
10
20
1°
0.2 kt
GT Mode
0
10
20
10
20
-3°
0.5 kt
NAV Mode GT Mode NAV Mode
If you encounter with such symptoms, perform the calibration following the procedure on the next
page.
Master
Gyrocompass
AD Converter
(Gyro Interface)