Furuno CI-35, CI-35H User Manual

9-52 Ashihara-cho,9-52 Ashihara-cho,

*00080797601**00080797601*

*OME72440C00**OME72440C00*

Nishinomiya, JapanNishinomiya, Japan

Telephone :Telephone : 0798-65-21110798-65-2111 Telefax :Telefax : 0798-65-42000798-65-4200

Your Local Agent/DealerYour Local Agent/Dealer

ll rights reserved.

PUB.No.PUB.No. OME-72440OME-72440

(( TATATATA ))

CI-35/35HCI-35/35H

Printed in JapanPrinted in Japan

FIRST EDITION :FIRST EDITION : FEB.FEB. 19971997

C :C : MAY.MAY. 13,200213,2002

* 0 0 0 8 0 7 9 7 6 0 1 ** 0 0 0 8 0 7 9 7 6 0 1 *

*OME72440C00**OME72440C00*

* O M E 7 2 4 4 0 C 0 0 ** O M E 7 2 4 4 0 C 0 0 *

SAFETY INSTRUCTIONS

"DANGER", "W ARNING" and "CAUTION" notices appear throughout this manual. It is the responsibility of the operator of the equipment to read, understand and follow these notices. If you have any questions regarding these safety instructions, please contact a FURUNO agent or dealer.

This notice indicates a potentially hazardous situation which, if not

DANGER

WARNING

avoided, will result in death or serious injury.

This notice indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.

CAUTION

This notice indicates a potentially hazardous situation which, if not avoided, could result in minor or moderate injury, or property damage.

iiiiiiiiiiiii

WARNING

CAUTION

Do not open the cover of the equipment.

This equipment uses high voltage electricity which can shock, burn, or cause death. Only qualified personnel should work inside the equipment.

Do not disassemble or modify the equipment.

Fire, electrical shock or serious injury can result.

Immediately turn off the power at the ship’s mains switchboard if water or foreign object falls into the equipment or the equipment is emitting smoke or fire.

Continued use of the equipment can cause fire, electrical shock or serious injury.

Do not place liquid-filled containers on the top of the equipment.

Fire or electrical shock can result if a liquid spills into the equipment.

Do not place heater near the equipment.

Heat can melt the power cord, which can result in fire or electrical shock.

Do not operate the unit with wet hands.

Electrical shock can result.

Use the correct fuse.

Use of the wrong fuse can cause fire or equipment damage.

A warning label is attached to the equipment. Do not remove the label. If the label is missing or damaged, contact a FURUNO agent or dealer about replacement.

WARNING

To avoid electrical shock, do not remove cover. No user-serviceable parts inside.

Name: Warning Label (1) Type: 86-003-1011-0 Code No.: 100-236-230

SAFETY INSTRUCTIONS ________________________________ i to ii

TABLES FOR RECORDING USER PRESETS _______________ v to x

CHAPTER 1. GENERAL_______________________________1-1 to 1-8

1. FEATURES ..................................................................................... 1-1

2. PRINCIPLE OF MEASUREMENT .................................................. 1-2

3. TIDE, NA V-TIDE & TIDE DIFFERENTIAL....................................... 1-5

CHAPTER 2. OPERATION _____________________________2-1 to 2-4

1. CONTROL PANEL LAYOUT ........................................................... 2-1

2. FUNCTION OF KEYS AND CONTROLS........................................ 2-2

3. OPERATING PROCEDURE ........................................................... 2-4

CHAPTER 3. DISPLAY _______________________________3-1 to 3-18

1. DISPLAY SAMPLES ....................................................................... 3-1

2. HOW TO READ THE DISPLAY ...................................................... 3-2

FUNDAMENTAL DATA SECTION .....................................................3-3 to 3-8

SHIP’S SPEED/COURSE Display...................................................... 3-3

TRACKING MODE Display ................................................................ 3-4

ERROR Status Display....................................................................... 3-5

TIDE SPEED/DIRECTION Display..................................................... 3-6

PRESENT TIME Display .................................................................... 3-8

TRIP TIME/DISTANCE Display .......................................................... 3-8

DRIFT/TIDE DIF SECTION ..................................................................... 3-9

SET & DRIFT Display......................................................................... 3-9

TIDE DIFFERENTIAL Display ............................................................ 3-9

iii

TIDE VECTOR/COURSE PLOT SECTION.....................................3-10 to 3-15

TIDE VECTOR Display...................................................................... 3-10

TIDE HISTORY Display......................................................................3-11

COURSE PLOT Display .................................................................... 3-12

TIDE EFFECT Display....................................................................... 3-13

DRIFT Display ................................................................................... 3-15

HEAD-UP/NORTH-UP Presentation ................................................. 3-15

RANGE CURSOR ............................................................................. 3-15

ECHO LEVEL SECTION........................................................................ 3-16

ECHO LEVEL Display ....................................................................... 3-16

MISCELLANEOUS DATA...............................................................3-17 to 3-18

WATER TEMPERATURE Display ..................................................... 3-17

MISCELLANEOUS DATA Display ..................................................... 3-18

CHAPTER 4. SETTING OPERATING CONDITIONS ________4-1 to 4-16

1. BASIC MENU.................................................................................. 4-1

MENU 1 .............................................................................................. 4-2

MENU 2 .............................................................................................. 4-4

MENU 3 .............................................................................................. 4-6

MENU 4 .............................................................................................. 4-8

2. RANGE SET MENU....................................................................... 4-10

3. ALARM SET MENU ....................................................................... 4-11

CHAPTER 5. TROUBLESHOOTING _____________________5-1 to 5-4

1. SELF-CHECK ................................................................................. 5-1

2. ERROR INDICATION...................................................................... 5-4

3. INTERNAL BATTERY ..................................................................... 5-5

SPECIFICATION ___________________________________AP-1 to AP-5

TABLES FOR RECORDING USER

ITEM

USER PRESET : selected REF TIDE DIF TIDE AVERAGE TIDE HISTORY LAYER1 LAYER2 LAYER3 TIDE DIF DSP DRIFT DSP TEMP DSP ECHO LEV DSP BACKGROUND

LAYER1

LAYER2

LAYER3 0 min 15 sec

1 min 1 min

2 min 5 min

3 min 10 min

4 min 30 min

5 min

1 hour ON ON ON ON DRIFT ON COLOR NORMAL

OFF OFF OFF OFF SPEED OFF GRAPH 1

OFF

FAC. SETTING LAYER1 2 min (**) 15 sec ON ON ON ON DRIFT ON COLOR NORMAL

(**) “2 min” or longer averaging time is desirable to obtain stable and smooth response of tide/tide differential display.

ITEM USER PRESET : selected REF DEPTH MENU SELECT

OFF LOCK

E/S UNLOCK

FAC. SETTING OFF LOCK

ITEM

USER PRESET : selected SHIP SPD AVE DRAFT WT SPD DEPTH HEEL ANGLE TRIM ANGLE GT SPD CALIB WT SPD CALIB BEARING CALIB EXT KP1 DIST EXT KP2 DIST BTM TIDE TRK

15 sec [ ] m [ ] m [ ] ° [ ] ° [ ] % [ ] % [ ] ° [ ] m [ ] m

OFF

30 sec

60 sec

0.0 to 25.6 m

-12.8 to +12.7°

-12.8 to +12.7%

-12.8 to +12.7°

0.0 to 25.6 m

0.0 to 25.6 m ON

FAC. SETTING 15 sec

0.0 m

2.0 m

0.0°

0.0%

0.0°

0.0 m

0.0 m OFF

* * * * * *

90 sec

PRESETS

The CI-30/35H provides menus to preset, various measuring and display conditions to customize the equipment precisely for your operating conditions.

The form below is provided to record user presets, so they can be restored in the event of loss by misoperation or by maintenance/service work.

1) BASIC MENU (Display/measuring conditions)

[MENU 1]

[MENU 2]

[MENU 3]

ITEM

TIME DATA

WT SPEED NAV FORMAT

* *

NAV AID NAV DATA

TIME INT

CRS CAL MODE

CRS CAL EXEC

TIDE OUT INT

INT T/D CIF GPS L/L

[ ] min

START

15 sec

USER PRESET : selected EXT NAV-TIDE NMEA

LORAN-C

SPD

1 to 10 min (in 1 min steps)

NAV

To start calibration, select START and press EVENT key.

30 sec

DECCA

MAN

1 min

2) RANGE MENU (Speed/distance/depth ranges)

2 min

LORAN-A

5 min

ALL

10 min

FAC. SETTING INT T/D CIF ALL SPD 1 min MAN

- 15 sec

ITEM SPEED RANGE DIST RANGE ECHO DEPTH ECHO SHIFT

[ ] kt [ ] NM [ ] m [ ]

3) RANGE MENU

ITEM

1ST LAYER

2ND LAYER

3RD LAYER

SHALLOW T/D

DEEP T/D

SHIP SPEED

TRIP

Marks on the ALARM MENU Filled star ( ) : alarm active Hollow star ( ) : alarm inactive Active speaker ( ) : speaker enabled Inactive speaker ( ) : speaker disabled

SPD DIR SPD DIR SPD DIR SPD DIR SPD DIR SPD CRS DIST TIME

1.0 to 30.0 kt

0.1 to 5.0 NM 50 to 700 m 1 to 36

SET ON/OFF

ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF

USER PRESET

MIN [ ] kt [ ]° [ ] kt [ ]° [ ] kt [ ]° [ ] kt [ ]° [ ] kt [ ]° [ ] kt [ ]° [ ] NM [ ]

MAX [ ] kt [ ]° [ ] kt [ ]° [ ] kt [ ]° [ ] kt [ ]° [ ] kt [ ]° [ ] kt [ ]° [ ] NM [ ]

SP ON/OFF

ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF

FAC. SETTING

2.0 kt

1.0 NM 50 m 1

FAC. SETTING SET OFF / SP ON SET OFF / SP ON SET OFF / SP ON SET OFF / SP ON SET OFF / SP ON SET OFF / SP ON SET OFF / SP ON SET OFF / SP ON SET OFF / SP ON SET OFF / SP ON SET OFF / SP ON SET OFF / SP ON SET OFF / SP ON SET OFF / SP ON

Note: 1. Descriptions of menu items and the procedures for presetting them begin on page 4-1.

2. To clear user presets and automatically restore factory settings, select “FACTORY” on the BASIC MENU2- “MENU SET”. (Note that the user presets for “TEMP DSP” and “ECHO LEV DSP” in MENU1 are not cleared by this operation.)

3. Items marked with “

” are user changeable. Items marked with “*” should not be changed needlessly once they are set at installation. Needless change can degrade the accuracy of measurements.

[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 compensation, weather compensation, etc.) are made correctly.

2. Manipulate the AD converter to obtain the same reading as you read on the master gyrocompass. (Do not make adjustment while the ship is turning.)

Master Gyrocompass

AD Converter

(Gyro Interface)

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.

GT Mode

1°

0.2

-3°

0.5

NAV Mode

GT Mode NAV Mode

If you encounter with such symptoms, perform the calibration following the procedure on the next page.

vii

CALIBRATING COURSE OFFSET (Automatic)

A. When ground-tracking is attainable:

1. Make sure the navaid (GPS) is working correctly and accurately.

2. On CI-35/35H, select ground tracking mode. (Press the TRACKING MODE key to see the “GT” mode indication on the display.)

3. In Menu 4, set ‘CRS CAL MODE’ to “GT”.

4. Run your boat at a speed about 10 kts, keeping the same direction. T o minimize the effect of gyro speed error, it is desirable to run along parallels (i.e., eastward or westward).

5. In Menu 4, place the cursor on “START” (‘CRS CAL EXEC’) and then press the EVENT key . As soon as you press the EVENT, “0.0” should appear in reverse text at the upper-right part of the display. After 2 mile-run, the display will show the course calibration angle (result of calculation) in normal text.

Course made good by CI-35/35H plus Gyro

Start Point

EVENT pressed

2 n.m. (approx)

Lead run

Course made good by ext. navaid (GPS)

Course calib. angle calibrated to fit these

two courses made good

B. When ground-tracking is unattainable:

1. Make sure the navaid (GPS) is working correctly and accurately.

2. On CI-35/35H, select nav-aided mode. (Press the TRACKING MODE key to see the “NA V” mode indication on the display.)

3. In Menu 4, set ‘CRS CAL MODE’ to “NAV”.

4. Run your boat at a speed about 10 kts, keeping the same direction. T o minimize the effect of gyro speed error, it is desirable to run along parallels (i.e., eastward or westward).

6. When the boat has run for 5 minutes, turn your heading almost 180˚ and steer back to the start point. After 10 minute-run, the display will show the course calibration angle (result of calculation) in normal text.

Start Point

EVENT pressed

Lead run

calibrated to equalize these tides

5 minutes (half way)

off the track by 5 to 10° not to get on own wake

viii

WHY IS GYRO DATA IMPORTANT IN NAV-AIDED MODE?

If you consider the difference of tide vector calculations is ground-tracking mode and in nav-aided mode, you will realize how important the gyro (heading) information is.

Tide Calculation in Ground-Tracking Mode

In ground-tracking mode, the CI-35/35H derives tide information from the following data.

(1) Ship’s speed/course based on ground

(ground speed)

(2) Ship’s speed/course based on target layer

(water speed)

(3) Bearing of ship’s bow

(Heading by gyro)

Both ground speed (1) and water speed (2) are sensed by the common transducers mounted on the hull. Thus, they are the speed vectors with respect to the ship’s bow. No matter what the true bearing of ship’ s heading be, the relative angle of these two vectors does not change. The tide vector is simply given as the difference of these two speed vectors.

: True bearing of ship’s bow (ref. north)

: Gyro reading

: Direction of ground speed (ref. bow)

: Direction of water speed (ref. bow)

True north

Ship’s bow

eGyro reading

wWater speed vector

qGround speed vector

Tide Vector

The heading data by gyro (3) is used after the tide vector calculation just to express the vector directions in true bearings (north referenced).

Even if the gyro data contains error, the sizes and relative angles of vectors do not change. The gyro error only affects the bearing indication of each vector .

Without gyro error

True north

Gyro error

eGyro reading

Ship’s bow

qGround speed vector

Tide Vector

wWater speed vector

With gyro error

True bearing of each speed vector contains fixed error. But, their sizes and relative angles are maintained despite the gyro error.

Tide Calculation in Nav-Aided Mode

In nav-aided mode, the CI-35/35H derives tide information from the following data.

(1) Ship’s speed/course sensed by the external navigator (GPS)

(nav speed = pseudo ground speed)

(2) Ship’s speed/course based on target layer

(water speed)

(3) Bearing of ship’s bow

(Heading by gyro)

Here, nav speed (1) is the ship’ s speed vector sensed by the external navigator, and the moving direction is expressed with respect to true north.

While the water speed (2) is the ship’s speed vector measured by CI-35/35H using the Doppler shifts against the measuring layer, and accordingly its direction is expressed with respect to the ship’s bow.

As the directional reference of these two vectors are different (north vs ship’ s bow), we can not simply calculate the difference of vectors to obtain the tide vector in question.

So the direction of water speed vector (2) is converted to true bearing (north reference) by using the gyro data, and then the tide vector is calculated.

If the gyro data contains some error, the true bearing of the water speed vector changes (rotates) accordingly . While the bearing of the nav speed vector does not change with the gyro error. (The relative angle of these two changes.)

In other words the tide vector, given as a difference of these two speed vectors, changes in size (speed) and bearing by the gyro error . (Error in size and bearing mean the tide vector is unreliable and useless.)

: True bearing of ship’s bow (ref. north)

: Gyro reading

: True bearing of nav speed (ref. north)

: Direction of water speed (ref. bow)

True north

eGyro reading

HθA

Ship’s bow

Tide Vector

wWater speed vector

qNav speed vector

Without gyro error

True north

Gyro error

eGyro reading

Ship’s bow

wWater speed vector

qNav speed vector

You may now realize that the gyro data in nav-aided mode is very important and it has to be accurate enough for reliable tide data.

Relative angle of water speed vector and

To obtain dependable tide/tide differential data, it is desirable to reduce the gyro error below 1 degree.

nav speed vector changes with gyro error. Accordingly, the size (speed) and direction of tide vector change.

Note: The depth must be at least 40 m in order to calculate tide.

Tide Vector

With gyro error

CHAPTER 1. GENERAL

1. FEATURES

¡ The functions of CI-35 and CI-35H are same. CI-35H is type approved by MOT (Ministory of

Transportation).

¡ Even in deep waters where ground (bottom) reference is not available acoustically, the CI-35/

35H can provide absolute movements of measuring layers by receiving position (or speed) data from GPS navigator and heading data from gyro compass. It may be used on deep sea fishing boats or on ocean research vessels.

¡ The CI-35/35H consists of three major units; display unit; transceiver unit and hull unit (trans-

ducer), each compact enough to permit installation even on a small boat.

¡ Triple-beam system for automatic error compensation against pitching and rolling of vessel.

Single-mold transducer makes installation easy while maintaining mechanical beaming accuracy.

¡ Sounding frequency of 130 kHz provides high interference immunity from other acoustic equip-

ments. Intelligent digital signal processing technique adds tracking stability and measuring accuracy.

¡ Echo level display always on screen. Permits constant monitoring of signal conditions of three

sounding beams.

¡ Tide effect display plots movements of tides beneath the vessel’s course track. Helpful in esti-

mating three-dimensional deformation of cast net.

¡ Tide history display presents change of tide over last 24 sample points (24 hours maximum) ¡ Raw data output port provided for collecting and analyzing current data on a separate computer .

Note: When transmitting with the external transmission pulse (KP) taken from an external device (echosounder, sonar , etc.), the repetition rate of the KP should be more than 500 ms. The repetition rate may become shorter than 500 ms when the range setting on the external device is less than 100 m. Therefore, set the range on the external device to more than 100 m.

1-1

2. PRINCIPLE OF MEASUREMENT

When a moving vessel emits an acoustical pulse into the water at an angle, a portion of emitted energy is reflected from the seabed and other microscopic objects in the sound path, such as plankton or air bubbles. The frequency of the received signal is shifted from the transmitted frequency in proportion to relative velocity between the vessel and underwater reflecting objects. This is called Doppler Effect.

The CI-35/35H calculates and displays movements of ship and currents at specific depths by measuring Doppler shifts obtained from three separate directions.

Planktonic layer

Seabed

Ship’s Speed

(Here, speed is a vector value including velocity and direction.)

Frequency of reflected signal is shifted in proportion to relative speed between the vessel and reflecting objects.

Depending on the base of measurement, ship’s speed is expressed in two ways:

Ground tracking speed: Ship’s speed and course relative to seabed (fixed base)

(Absolute speed)

Water tracking speed: Ship’s speed and course relative to water layer just below the

(Relative speed)

vessel (floating base)

Nav-aided speed: Ship’s speed and course obtained by external navigation

(Absolute speed)

equipment (GPS)

1-2

GPS satellites

Water tracking speed

Ground tracking speed

Fixed

Nav-aided speed (Pseudo ground tracking speed)

Near-surface layer

:Base of measurement

Tide

Tide is movement of watermass at a particular depth. To know absolute tide (speed on ground), the following two data are required:

1 Ship’s speed and course based on ground 2 Ship’s speed and course based on measuring layer (A)

Absolute tide is, then, given as a difference of these two speed vectors.

Absolute Tide = 1 - 2

Layer (A)

Fixed

:Base of measurement

Nav-Tide

Nav-Tide is an absolute movement of watermass at a particular depth, taking speed information from the external navigator (GPS) as a pseudo ground tracking speed.

To calculate Nav-tide, the following two data are required:

1 Ship’s speed and course obtained by external navigation equipment (GPS) 2 Ship’s speed and course based on measuring layer (A)

Nav-tide is, then, given as a difference of these two speed vectors.

Absolute Tide = 1 - 2

GPS satellites

q Nav-aided speed (Pseudo ground tracking speed)

w Water tracking speed

:Base of measurement

Layer (A)

1-3

Tide Differential

Tide differential is a relative movement of tides at different depths, layer (A) and layer (B). To calculate tide differential, the following two data are used:

1 Ship’s speed and course based on layer (A) 2 Ship’s speed and course based on layer (B)

Tide differential between two layers is, then, given as a difference of these two speed vectors.

Tide Difference = 1 - 2 (Movement of layer B based on layer A)

or = 2 - 1 (Movement of layer A based on layer B)

Layer (A)

Layer (B)

:Base of measurement

1-4

3. TIDE, NAV -TIDE & TIDE DIFFERENTIAL

Tide

(Absolute tide)

Absolute tide can be measured in the ground tracking mode.

10 NM (1 hour trip)

Start of trip

Layer A

(Moving at 10 kt on ground)

(Moving at 3 kt on ground)

Fixed

End of trip

:Base of measurement

Assume that the ship and layer A are moving in the same direction, and ship’s speeds based on ground (Vg) and on layer A (Vwa) are measured as;

Vg = 10 kt (Ship’s speed based on ground) Vwa = 7 kt (Ship’s speed based on layer A).

Speed of layer A based on ground (C1) can be calculated as follows:

C1 = Vg - Vwa

= 10 - 7 = 3 (kt)

Nav-Tide

(Absolute tide)

Absolute tide can be measured in the nav-aided mode. Nav-aided ship’s speed (Vn) is equivalent to ship’s ground tracking speed in the ideal conditions.

That is, the nav-tide can be calculated by simply replacing Vg with Vn in the above equation.

1-5

Tide Differential

Tide differential is a relative movement of tides at different depths. It can be measured in the ground tracking, water tracking and nav-aided modes.

10 NM (1 hour trip)

Start of trip

Layer A

Layer B

(Moving)

2 kt

:Base of measurement

5 kt

End of trip

Assuming that the ship, layer A and layer B are moving in the same direction, and ship’s speeds based on layer A (Vwa) and on layer B (Vwb) are measured as;

Vwa = 8 kt (Ship’s speed based on layer A) Vwb= 5 kt (Ship’s speed based on layer B)

Tide differential calculations in ground tracking mode

As an absolute ship’s speed (Vg) is available in the ground tracking mode, tide speeds of layer A (C1) and layer B (C2) based on ground are calculated as follows:

C1 = Vg - Vwa (Speed of layer A based on ground) C2 = Vg - Vwb (Speed of layer B based on ground)

Thus, the tide differential (Cd) between layer A and layer B is;

Cd = C2 - C1

= (Vg - Vwb) - (Vg - Vwa) = Vwa - Vwb = 8 - 5 = 3 (kt)

Tide differential based on layer A

Speed of layer B viewed from layer A

1-6

Cd = C1 - C2

= (Vg - Vwa) - (Vg - Vwb) = Vwb - Vwa = 5 - 8 = -3 (kt)

Tide differential based on layer B

Speed of layer A viewed from layer B

In the water tracking mode, watermass just below the transducer (near-surface layer) is taken as the base of all measurements (virtual ground). Therefore, the ship and tide speeds in the water tracking mode are not absolute but relative to this near-surface layer.

Vw = 9 kt (Ship’s speed based on near-surface layer) Vwa = 8 kt (Ship’s speed based on layer A) Vwb= 5 kt (Ship’s speed based on layer B)

Start of trip

Nearsurface layer

Layer A

Layer B

1 kt

2 kt

10 NM (1 hour trip)

5 kt

End of trip

:Base of measurement

Assume that the ship and all measuring layers are moving in the same direciton, but at different speeds.

1-7

Tide differential calculations in water tracking mode

Tide speeds of layer A (C1) and layer B (C2) relative to near-surface layer (Vw) are calculated as follows:

D1 = Vw - Vwa (Speed of layer A based on near-surface layer) D2 = Vw - Vwb (Speed of layer B based on near-surface layer)

The tide differential (Dd) between layers A and layer B is;

Dd = D2 - D1

= (Vw - Vwb) - (Vw - Vwa) = Vwa - Vwb = 8 - 5 = 3 (kt)

Dd = D1 - D2

= (Vw - Vwa) - (Vw - Vwb) = Vwa - Vwb = 5 - 8 = -3 (kt)

Tide differential based on layer A

Speed of layer B viewed from layer A

Tide differential based on layer B

Speed of layer A viewed from layer B

If you compare the results of calculations on this page with the ones on preceding pages, you will find the tide differential of two layers is identical irrespective of tracking mode.

1-8

CHAPTER 2. OPERATION

1. CONTROL PANEL LAYOUT

Control panel

DEGAUSS button

Press this button when picture is distorted or coloration is unbalanced due to magnetization.

PWR

TIDE

EFFECT

DRIFT

TIDE

DIF

TRIP

TRACK

MODE

ALARM

RANGE

OFF

EVENT

COURSE

PLOT

HISTORY

MANUAL

TRACK

LAYERMENU

LYR

CONTRAST control

Adjusts display color contrast.

BRILLIANCE control

Adjusts display brightness.

DIMMER control

Adjusts illumination brightness of control panel and manual tracking indication lamp.

VOLUME control

Adjusts volume of key beep and audible alarm.

BRILLIANCE

10 0

DIMMER

CONTRAST

VOLUME

2-1

+ 48 hidden pages

Furuno CI-35, CI-35H User Manual

SAFETY INSTRUCTIONS

CONTENTS

CHAPTER 1. GENERAL

1. FEATURES

2. PRINCIPLE OF MEASUREMENT

3. TIDE, NAV -TIDE & TIDE DIFFERENTIAL

CHAPTER 2. OPERATION

1. CONTROL PANEL LAYOUT