ISO 25862:2009

INTERNATIONAL ISO
STANDARD 25862
First edition
2009-05-15
Ships and marine technology — Marine
magnetic compasses, binnacles and
azimuth reading devices
Navires et structures maritimes — Compas magnétiques marins,
habitacles et alidades
Reference number
©
ISO 2009
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©  ISO 2009
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ii © ISO 2009 – All rights reserved

Contents Page
1 Scope .1
2 Normative references.2
3 Terms and definitions .2
4 Magnetic compasses .2
5 Binnacles.9
6 Azimuth reading devices (class A and, if fitted, class B).13
7 Marking.14
8 Designation .14
Annex A (normative) General testing and certification of marine magnetic compasses, binnacles
and azimuth reading devices .15
Annex B (normative) Testing and certification of marine magnetic compasses .17
Annex C (normative) Testing and certification of azimuth reading devices.27
Annex D (normative) Type-testing and certification of binnacles .32
Annex E (normative) Positioning of magnetic compasses in ships.40
Annex F (normative) Determination of safe distances.45
Annex G (normative) Adjustment of magnetic compass deviation.46
Annex H (normative) Requirements of magnetic compass for lifeboats/rescue boats.48

iii © ISO 2009 – All rights reserved

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 25862 was prepared by Technical Committee ISO/TC 8, Ships and marine technology, Subcommittee
SC 6, Navigation.
This first edition of ISO 25862 cancels and replaces ISO 449:1997, ISO 613:2000, ISO 694:2000,
ISO 2269:1992 and ISO 10316:1990.

iv © ISO 2009 – All rights reserved

INTERNATIONAL STANDARD ISO 25862:2009(E)

Ships and marine technology — Marine magnetic compasses,
binnacles and azimuth reading devices
1 Scope
This International Standard gives requirements regarding construction and performance of marine magnetic
compasses for navigation and steering purposes, binnacles and azimuth reading devices.
According to the design of the ship, two types of binnacle are specified.
This International Standard applies to liquid-filled magnetic compasses:
⎯ intended for ship's navigation and steering purpose in sea navigation according to regulations in force;
⎯ having a direct reading system;
⎯ which may be of the reflecting, projecting or transmitting types.
In the context of this International Standard, a magnetic compass is an instrument consisting of a directional
system supported by a single pivot inside a bowl which is completely filled with liquid, and which is supported
in gimbals inside or outside the bowl. Compasses without gimbals are also covered by this International
Standard; the requirements relating to gimbals do not apply to such compasses.
This International Standard applies to
⎯ all ships to which SOLAS applies (ships of gross tonnage W 150 t, engaged on international voyages and
ships of gross tonnage W 500 t not engaged on international voyages) fitted with class A magnetic
compasses,
⎯ all ships to which SOLAS does not apply, fitted with the class A or class B magnetic compasses, and
⎯ lifeboats/rescue boats fitted with a class B magnetic compass (as specified in Annex H).
This International Standard does not apply to:
a) dry card compasses,
b) types of compass designed on principles different from those stated above or not complying with the
descriptions given, or
c) hand bearing compasses.
The requirements for the testing and certification, positioning in ships and the deviation adjustment of
compasses are given in the Annexes.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 1069:1973, Magnetic compasses and binnacles for sea navigation — Vocabulary
lEC 60945:2002, Maritime navigation and radiocommunication equipment and systems — General
requirements — Methods of testing and required test results
IMO Resolution A.382(X) Recommendations on performance standards for magnetic compasses
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1069 and the following apply.
3.1
magnetic control sensor
sensor using the geomagnetic field for feeding an automatic heading-control system, or controlling an off-course
alarm unit, or feeding other devices
3.2
minimum distance
distance measured between the nearest point of magnetic material which is part of the ship's structure and the
centre of the compass
NOTE The minimum distance for a standard compass is given in Figure E.1 and for a steering compass is given in
Figure E.2.
3.3
safe distance
distance measured between the nearest point of the item concerned and the centre of the compass
NOTE The safe distance is determined as specified in Annex F.
4 Magnetic compasses
4.1 Construction and materials
4.1.1 Magnetic material
The magnets used in the directional systems of magnetic compasses shall be of a suitable magnetic material
having a high remanence and coercivity of at least 18 kA/m. All other materials used in magnetic compasses,
other than transmitting compasses, shall be of non-magnetic material.
4.1.2 Lubber mark
In class A compasses, the distance between the lubber mark and the outer edge of the card shall be between
1,5 mm and 3,0 mm for direct reading and reflecting types and between 0,5 mm and 1,5 mm for projecting
compasses. The width of the lubber mark shall not be greater than 0,5° of the graduation of the card.
In class B compasses, the compass shall be fitted with at least one lubber mark, indicating the direction of the
ships head (the main lubber mark). Additional lubber marks are permissible.
2 © ISO 2009 – All rights reserved

The lubber mark shall be of such design as to allow the compass to be read from the steering position when
the bowl is tilted 10° in the case of a gimbal compass or 30° in other cases.
4.1.3 Position of the card (class A only)
When the verge ring and the seating for the azimuth reading device are both horizontal, the graduated edge of
the card, the lubber mark if a point, the pivot point and the outer gimbal axis shall lie within 1 mm of the
horizontal plane passing through the gimbal axis fixed to the bowl.
4.1.4 Angle of gimbal axes and intersection of vertical planes passing through them
The angle formed by the outer and inner gimbal axes shall be of the values given in Table 1. The vertical
planes through the gimbal axes shall intersect to within 1 mm of the pivot point. Any end play shall not cause
these tolerances to be exceeded.
Table 1 — Angle of gimbal axes
Magnetic compasses Angle of gimbal axes
Class A (90 ± 1)°
Class B (90 ± 2)°
The outer gimbal axis shall be in the fore and aft direction. For compasses without gimbals, which are also
covered by this International Standard, the requirements relating to gimbals do not apply.
4.1.5 Thickness of the top glass cover (class A only)
The thickness of the top glass cover and of the bottom glass of the compass shall be not less than 4,5 mm, if
non-toughened, and not less than 3,0 mm, if toughened. These values apply also to the thickness of the top
glass in hemispherical compasses. If material other than glass is used, it shall be of equivalent strength.
4.1.6 Constructional condition within the temperature range
Within the temperature ranges given in Table 2:
a) the compass shall operate satisfactorily;
b) the liquid in the compass bowl shall remain clear and free from bubbles and neither emulsify nor freeze;
c) there shall be neither inward leakage of air nor outward leakage of liquid. No bubble shall form in a
compass unless it is specially provided to compensate for expansion;
NOTE A bubble provided in a compass to compensate for expansion shall not inconvenience the functioning and
reading of the compass.
d) the internal paint shall not blister, crack or discolour appreciably;
e) for class A compasses, that the force exerted on the pivot bearing, in the liquid at 20 °C, by the directional
system is between 0,04 N and 0,1 N when the card diameter is 165 mm or less, and is between 0,04 N
and 0,14 N when the card diameter is larger than 165 mm;
f) for class B compasses, the supporting force shall be such that the directional system always remains in
contact with its pivot;
g) the material of the compass card shall not distort.
Table 2 — Temperature range
Magnetic compasses Temperature ranges
Class A
−30 °C to +60 °C
Class B
−20 °C to +60 °C
4.1.7 Horizontal position
The compass bowl shall be balanced so that its verge ring or top glass cover settles in the horizontal plane to
within 2° when the gimbal ring is fixed in a horizontal position; this shall be so whether the azimuth reading
device or magnifying glass is in place or not.
4.2 Mounting
4.2.1 Tilt of supporting device
The bowl of the compass shall be mounted so that the verge ring remains horizontal to within 2° when the
binnacle is tilted 40° in class A, 30° in class B in any direction and in such a manner that the compass cannot
be dislodged under any conditions of sea or weather.
The inner and outer gimbal bearings shall be of the same type.
4.2.2 Freedom of the card of the compass with no supporting gimbal
In compasses in which no supporting gimbal is provided, the freedom of the card shall be 30° in all directions.
4.3 Directional system
4.3.1 Moment of inertia
The moment of inertia of the directional system shall be approximately the same about all horizontal axes
passing through the point of support on the pivot jewel.
4.3.2 Suspension (class A only)
The directional system shall be retained in position by suitable means and remain free when the bowl is tilted
10° in any direction.
4.3.3 Magnetic moment (class A only)
The magnetic moment of the magnets in the directional system shall not be less than the value given in
Figure 1.
4 © ISO 2009 – All rights reserved

Key
X card diameter, expressed in mm
Y magnetic moments, expressed in A·m
Figure 1 — Magnetic moments of liquid filled compasses (minimum requirements)
4.3.4 Settling time
Following an initial deflection of the card of 90° from the magnetic meridian, the time taken to return finally to
within 1° of the magnetic meridian shall not exceed 240/ H at a temperature of (20 ± 3) °C, where H is the
horizontal component of the magnetic flux density in microteslas (µT) at the place of testing.
4.3.5 Tilt of the directional system with regard to the vertical field (class A only)
The directional system shall be so constructed, or balanced in such a way, that it does not incline more than
0,5° from the horizontal plane when the vertical flux density is zero. The inclination shall not change by more
than 3° when the vertical flux density changes 100 µT.
4.3.6 Supporting force (class A only)
The force exerted on the pivot bearing, in the liquid used, by the directional system shall be between 0,04 N
and 0,1 N when the card diameter is 165 mm or less, and shall be between 0,04 N and 0,14 N when the card
diameter is larger than 165 mm.
4.4 Compass card
4.4.1 Graduation
The compass card shall be graduated with 360 single degrees, starting from North in the clockwise direction
as viewed from above. Each tenth degree should be marked with the three corresponding numbers. North
should also be indicated by “000°”. The cardinal points shall be indicated by the capital letters “N”,“S”,“E” and
“W”; the intermediate points may also be marked. Alternatively, the North point may be indicated by a suitable
symbol.
The card shall be numbered as given in Table 3.
Table 3 — Graduation of the card
Magnetic compasses Equal interval of the graduation Card numbered
Class A 1° Every 10°
Class B Not more than 5° Every 30°

Where the compass card is printed on both sides, the graduations shall coincide with a tolerance of 0,2°.
4.4.2 Diameter of the card
The diameter of the compass card for binnacles of the following types are as given in Table 4.
Table 4 — Diameter of the card
Magnetic compasses Binnacle types Diameter of the card
A1 165 mm or more
Class A
A2 125 mm or more
A1
Class B 125 mm or more
A2
NOTE 1 Binnacle type A1 (see 5.1) is defined as the height of the binnacle being not less than
1 m; if the height of the binnacle is less than 1 m, it is binnacle type A2 (see 5.2).
NOTE 2 Diameter of the card of the magnetic compass for lifeboat/rescue boats is given in H.2.1.
6 © ISO 2009 – All rights reserved

4.4.3 Readability
Steering compasses of each class shall be able to be read by a person with normal vision at a distance from
the magnetic compasses as given in Table 5 in both daylight and artificial light, the graduations on the card
being contained within a sector whose width is not less than 15° to each side of the lubber mark. The use of a
magnifying glass is permitted.
For reflecting and projecting compasses, the lubber mark shall be visible and the 30° sector of the card shall
be readable by a person with normal vision at a distance of 1 m from the periscope tube.
Table 5 — Readable distance
Magnetic compasses Readable distance of compasses
Class A 1,4 m
Class B 1,0 m
4.4.4 Bearing compasses
If a bearing compass is provided with a scale graduated in degrees for the measurement of bearings relative
to the ship's head, the scale shall be graduated 360° in a clockwise direction, where zero, as seen through the
azimuth reading device, indicates the direction of the ship's head.
4.5 Accuracy
4.5.1 Directional error
The directional error is a directional system constructional error. It is composed of:
a) error of magnet orientation with regard to the graduation of the card (collimation error);
b) inaccuracies of the compass card graduation;
c) eccentricity of the compass card graduation with regard to the rotation centre of the card.
The directional error shall on no heading exceed the values as given in Table 6.
Table 6 — Accuracy of the directional errors
Magnetic compasses Permissible directional error
Class A 0,5°
Class B 1,5°
In transmitting compasses, the directional error applies to the compass without fluxgate. The fluxgate of a
transmitting compass shall be placed so that the influence on the card heading shall not exceed 0,5° in the
case of class A.
NOTE If the test is undertaken in the compass bowl, the resulting value then includes the deviation due to any
magnetic material in the compass and/or in the fluxgate.
4.5.2 Error of lubber marks
Lubber error is a constructional error of the compass bowl and gimbal, which depends on the relative position
of the main lubber mark (if it is fixed), the pivot bearing, and the direction of the outer gimbal axis.
No lubber error shall exceed the values given in Table 7.
Table 7 — Lubber errors
Magnetic compasses Maximum lubber error
Class A 0,5°
Class B 1,0°
4.5.3 Error due to friction
With the compass at a temperature of (20 ± 3) °C, the card is given an initial deflection (for values see
Table 8) first on one side of the meridian and then on the other. It shall return to its original position within the
values given in Table 8, where H is as defined in 4.3.4.
Table 8 — Error due to friction
Magnetic compasses Initial deflection Maximum angle to return
Class A 2° Less than (3/H)°
Class B 5° Less than (9/H)°
4.5.4 Swirl error
With the compass at a temperature of (20 ± 3) °C and rotating at a uniform rotational speed of 6°/s in the
horizontal plane, the card deflection from the magnetic meridian when the bowl has been rotated 180° shall
not exceed the values given in Table 9.
Alternatively, when rotating at a uniform rotational speed of 1,5°/s, the card deflection, measured after the
bowl has been rotated 360°, shall at no point exceed the values given in Table 9, where H is as defined in
4.3.4.
Table 9 — Swirl error
Card deflection
Magnetic compasses
Rotational speed: 6°/s Rotational speed: 1,5°/s
measured after rotated 180° measured after rotated 360°
With a card 200 mm or more
(54/H)°
in diameter
Class A
(108/H)°
With a card less than 200 mm
(36/H)°
in diameter
Class B (40/H)°
8 © ISO 2009 – All rights reserved

4.5.5 Induction error (class A only)
To avoid the induction error which is caused by an inadequate arrangement of magnetic elements in the
directional system and introduced by magnetic induction in correctors (iron spheres or similar conventional
correctors) of coefficient D due to the magnetic elements in the directional system, one of the following
requirements shall be fulfilled:
a) The value of the ratio of coefficient H to coefficient D shall not exceed 0,08.
b) The coefficient F of the sextantal deviation caused by a small magnet, less than 50 mm in length, placed
in the same horizontal plane as the magnetic elements at a tangential distance of about 40 cm from the
centre of the directional system, is less than 0,01 of coefficient B of the semicircular deviation.
4.5.6 Mounting error of azimuth reading device
Where the azimuth reading device is pivoted on the compass bowl, the vertical axis of the device shall be
within 0,5 mm of the pivot point.
4.5.7 Error due to eccentricity of the verge ring (class A only)
If the verge ring is graduated, the perpendicular to the plane of this ring through the centre of the graduations
shall be within 0,5 mm of the pivot point.
4.6 Environmental conditions tests of magnetic compasses (class A only)
Damp heat test and rain and spray tests shall be carried out as specified in IEC 60945 and all requirements
shall be met.
Optionally, the vibration test may be additionally carried out as specified in IEC 60945.
NOTE Environmental conditions tests of the magnetic compass for lifeboat/rescue boats are given in H.2.3.
5 Binnacles
Depending on the type of ship on which it shall be fixed, one of two types of binnacle may be used: type A1 or
type A2. The characteristics of the two types are as specified in 5.1 and 5.2.
Magnetic compasses and binnacles are combined to be used as given in Table 10.
Table 10 — Types of binnacles
Magnetic compasses Binnacles
Class A Type A1 Type A2
Class B Type A1 Type A2
5.1 Binnacle type A1
Binnacle type A1 shall be of such a height that the magnets of the directional system of the compass are at
least 1,0 m above the under-surface of the binnacle deck fittings and meet the requirements given in 5.1.1 to
5.1.5.
5.1.1 Construction and materials
Only high quality non-magnetic materials of sufficient strength shall be used for the construction
5.1.1.1
of binnacles, helmet and box, brackets and holding-down bolts.
5.1.1.2 Provision shall be made in the binnacle to allow correction of any misalignment thereof in respect
of the fore and aft line of the ship, by an angle of not less than 4° and not more than 6°.
5.1.2 Provision for correction of deviation (if fitted in class B compasses)
5.1.2.1 Material
Where corrector magnets are used, they shall be of a suitable magnetic material of high remanence and
coercivity of not less than 11,2 kA/m.
Material used for correcting induced fields shall have a high permeability, a low coercivity and a negligible
remanence.
Built-in magnets must be capable of being put into a neutral position or be removable. Built-in magnets for B
and C correction must not produce a heeling error.
5.1.2.2 Compensation for horizontal permanent magnetism
Binnacles shall contain a device for correcting the deviation due to the horizontal components of the ship's
permanent magnetism. This device shall be capable of correcting a coefficient B of up to at least (720/H)° and
a coefficient C of up to at least (720/H)°, where H is as defined in 4.3.4.
Provision shall be made in binnacles so that no magnets of the correcting system come so close to the
directional system as to distort the field and produce a deviation of more than (20/H)° on any course, even
when there is a heel or pitch of 15°.
5.1.2.3 Correction for heeling error
Binnacles shall contain a device for correcting heeling error. This device shall be adjustable and capable of
providing a vertical magnetic field at the magnets of the directional system over the range +75 µT to −75 µT.
Provision shall be made in binnacles so that no magnets of the correcting system come so close to the
directional system as to distort the field and produce a deviation of more than (20/H)° expected heeling errors
on any course, even when there is a heel or pitch of 15°, where H is as defined in 4.3.4.
5.1.2.4 Compensation for horizontal induced fields due to the horizontal component of the earth's
magnetic field in the soft iron in a ship
Binnacles shall be provided with a device for compensating the horizontal magnetic fields due to induction
caused by the horizontal component of the earth's magnetic field in the soft iron in a ship. This device shall be
capable of correcting a coefficient D of up to 10°.
When binnacles are vertical, and compensation is effected by spheres, the centre of the device shall not be
further than 15 mm from the horizontal plane passing through the magnetic element of the directional system.
5.1.2.5 Compensation for horizontal induced fields due to the vertical component of the earth’s
magnetic field in the soft iron in a ship
Binnacles shall be provided with a device for compensating the horizontal magnetic fields due to induction
caused by the vertical component of the earth's magnetic fields in the soft iron in a ship. When a Flinders' bar
is used, it may be hollow, provided the diameter of the hole does not exceed 40 % of the diameter of the bar.
10 © ISO 2009 – All rights reserved

When binnacles are vertical, the magnetic pole of the compensating device shall lie in the same horizontal
plane as the centres of the magnets of the directional system. When a Flinders' bar is used, its magnetic pole
shall be taken at 1/12 of its length from the end.
5.1.2.6 Positions and attachment of correcting devices
Provision shall be made in binnacles for recording the positions of the correcting devices referred to in 5.1.2.2,
5.1.2.3 and 5.1.2.4.
Provision shall be made for all correcting devices to be satisfactorily secured after adjustment.
5.1.2.7 Corrector coils
Provision may be made for the fitting of corrector coils to provide compensation, if the ship is fitted with
degaussing coils.
5.1.3 Accuracy of fore and aft marks
Where fore and aft marks are provided on binnacles, they shall be in the same vertical plane to within 0,5° as
the axis of the fore and aft gimbal bearings.
5.1.4 Illumination
The binnacle shall contain adequate provision for illuminating the card and the lubber mark by the ship's
electric supply and from an emergency light source.
In projector and reflector binnacles these shall provide a clear image at the helmsman's position.
A device shall be provided for dimming the electric light from the ship's mains.
The electric lamps, fittings and wirings shall have no influence on the directional system.
5.1.5 Other requirements
Binnacles shall satisfy the following tests specified in IEC 60945 (Ed.4, 2001-02).
1) damp heat,
2) corrosion (salt mist).
5.2 Binnacle type A2
This binnacle is used in sea navigation when the design of the ship makes the provision of a full-sized
binnacle impracticable.
With regard to height, there are no requirements provided that binnacles meet the following requirements.
5.2.1 Construction and materials
Only high quality non-magnetic material of sufficient strength shall be used.
5.2.2 Provision for correction of deviation
5.2.2.1 Material
Where correcting magnets are used they shall be of suitable magnetic material of high remanence and
coercivity not less than 11,2 kA/m. Material used for correcting induced fields shall have a high permeability, a
low coercivity and a low remanence.
5.2.2.2 Compensation for horizontal permanent magnetism
Binnacles shall contain a device for correcting the deviation due to the horizontal components of the ship's
permanent magnetism. This device shall be capable of correcting a coefficient B of up to at least (720/H)° and
a coefficient C of up to at least (720/H)°, where H is as defined in 4.3.4.
Provision shall be made in binnacles so that no magnets of the correcting system come so close to the
directional system as to distort the field and produce a deviation of more than (40/H)° on any course, even
when there is a heel or pitch of 15°.
5.2.2.3 Correction for heeling error
Binnacles shall contain a device for correcting the heeling error. This device shall be adjustable and capable
of providing a vertical field at the position of the directional system over the range of +75 µT to −75 µT.
Provision shall be made in binnacles so that no magnets of the correcting system come so close to the
directional system as to distort the field and produce a deviation of more than (80/H)° on any course, even
when there is a heel or pitch of 15°, where H is as defined in 4.3.4.
NOTE The magnetic fields produced by the devices referred to in 5.2.2.2 and 5.2.2.3 shall be as uniform as possible
in the space swept by the directional system and should in no case introduce a significant sextantal error.
5.2.2.4 Compensation for horizontal induced fields due to the horizontal component of the earth's
magnetic field in the soft iron of the ship
Binnacles may be provided with a device for compensating the horizontal magnetic fields due to induction
caused by the horizontal component of the earth's magnetic field in the soft iron of the ship. This device shall
be capable of correcting a coefficient D of up to 7°.
When binnacles are vertical and compensation is effected by spheres, the centre of the device shall not be
further than 15 mm from the horizontal plane passing through the magnetic element of the directional system.
5.2.2.5 Compensation for horizontal induced fields due to the vertical component of the Earth's
magnetic field in the soft iron of the ship
Binnacles may be provided with a device for compensating the horizontal magnetic fields to the induction
caused by the vertical component of the Earth's magnetic field in the soft iron of the ship. When a Flinders' bar
is used, it may be hollow, provided that the diameter of the hole does not exceed 40 % of the diameter of the
bar.
When binnacles are vertical, the magnetic pole of the device shall lie in the same horizontal plane as the
centres of the magnets of the directional system. When a Flinders' bar is used, its magnetic pole shall be
taken at 1/12 of its length from the end.
The distance between the vertical axis of a Flinders' bar from the centre of the card shall be at least 3,5 times
the length of the magnetic needles.
5.2.2.6 Attachment of correcting devices
Provision shall be made for all correcting devices to be satisfactorily secured after adjustment.
12 © ISO 2009 – All rights reserved

5.2.3 Accuracy of fore and aft marks
In order that the mounting may be undertaken accurately, fore and aft marks shall be provided and these shall
be within 0,5° (1,0° in class B) of the fore and aft axis of the gimbal bearings.
5.2.4 Illumination
The binnacle shall contain adequate provision for illuminating the card by the ship's electric supply and from
an emergency light source. In projector and reflector binnacles, these shall provide a clear image at the
helmsman's position. A device shall be provided for dimming the electric light from the ship's mains.
The electric lamps, fitting and wiring shall have no influence on the directional system.
5.2.5 Other requirements (class A only)
Binnacles shall satisfy the following tests specified in IEC 60945:
a) damp heat;
b) corrosion (salt mist).
6 Azimuth reading devices (class A and, if fitted, class B)
There shall be an appropriate azimuth reading device for the bearing compass. Types A1 and A2 binnacles
may be supplied with a suitable pelorus which may be fitted away from the binnacle.
6.1 Azimuth sight
The field of vision shall be at least 5° on each side of the line of sight and it shall be possible to take azimuths
of celestial bodies and bearings of distant objects whose altitudes are between 5° below and 60° (10° in
class B) above the horizontal.
The required accuracy of the azimuth shall be fulfilled with the group of azimuth reading devices described in
Annex C in the altitude range of 5° above to 50° above.
6.2 Azimuth reading devices with vanes
It shall be possible to take bearings of distant objects whose altitudes are between 5° below and 30° above
the horizontal.
6.3 Level
A level shall be provided for azimuth mirror or prism instruments.
This level shall be of accuracy within 1°.
7 Marking
The following parts shall be marked with the information, in the position indicated, given in Table 11.
Table 11 — Marking requirements
Position of manufacturer's name
Part Position of serial number on the part
or other means of type identification
Card
Card
Magnetic compasses
Verge ring
Verge ring
Gimbal ring or rings
Any conventional position,
Binnacle Not required
together with type marking
Azimuth reading device On top of the azimuth reading devices On top of the azimuth reading devices
The type of liquid used, if other than alcohol, shall be indicated on the bowl in the vicinity of the filling plug.
The marking shall be noted on the type-test certificate (see Annex D).
8 Designation
Magnetic compasses stated as complying with this International Standard shall be designated by the following
indications, in the order given:
⎯ type of compass (reflector, projector, transmitting);
⎯ number of this International Standard;
⎯ type of binnacle;
⎯ card diameter, in millimetres.
EXAMPLE Reflector magnetic compass, class A with binnacle type A2 and a card diameter of 180 mm is
designated: Reflector magnetic compass ISO 25862 - A2 - 180.
14 © ISO 2009 – All rights reserved

Annex A
(normative)
General testing and certification of marine magnetic compasses,
binnacles and azimuth reading devices
A.1 Introduction
This Annex gives general information about the testing and certifications on marine magnetic compasses,
azimuth reading devices and binnacles.
The testing and certification of:
⎯ magnetic compasses are as specified in Annex B;
⎯ azimuth reading devices are as specified in Annex C;
⎯ binnacles are as specified in Annex D.
A.2 Scope of testing
Annexes B, C and D specify type-test and individual test methods, and give the acceptable limits of the
characteristics necessary to state conformity of magnetic compasses, azimuth reading devices and binnacles
to the general specifications given in this International Standard.
A.3 Types of compasses to be tested
Testing shall be carried out on all class A and class B marine magnetic compasses, with or without a
transmitting system. All compasses, other than those compasses without gimbals which are used as steering
compasses only, shall be tested with their gimbal rings and outer gimbal bearings.
A.4 Test conditions
Type-testing shall be carried out before the instruments covered come into regular service. Type-testing is
acceptable only for new devices.
Individual testing shall be carried out before installation on-board ship; it should also be done periodically and
after repair. For individual testing, all devices shall be in a clean and serviceable state when submitted for
testing.
Unless otherwise stated, all tests shall be carried out at a temperature of (20 ± 3) °C.
A.5 Certification
Devices which have passed the type-tests or the individual tests and comply with the requirements shall be
certified in the language of the test authority and in English.
Each type-test certificate is valid exclusively for the model tested. In case of alterations or technical
improvements which affect its compliance with this International Standard, the model shall be given a new
identification number or mark and the type-test repeated. All alterations shall be submitted to the original test
authority who will decide whether a new type-test is necessary (see the certificate form in the last part of
Annexes B, C and D).
Copies of the certificate shall be issued on demand. They shall be explicitly marked “copy”.
Acceptance of type-test certificates and individual test certificates between countries will be a matter for
mutual agreement.
16 © ISO 2009 – All rights reserved

Annex B
(normative)
Testing and certification of marine magnetic compasses
B.1 Manufacturer's statement
The manufacturer shall produce a written statement covering those requirements which cannot be ascertained
during a type-test (see B.4). The statement shall include the following points:
a) the coercivity and magnetic moment of the directional magnets;
b) that the paint inside the compass is of good quality and that over a period of two years it is not likely to
deteriorate to such an extent as to make the compass unusable, either as a result of the change of
temperature over the range of −30 °C to +60 °C or any other cause (for example the legibility of
graduations shall not be impaired by discolouration or blistering);
c) under the conditions described in b), that the compass liquid is not likely to show any appreciable
discolouration such as to render the compass unusable;
d) whether toughened or non-toughened glass is used for the top and bottom glass covers and its thickness
or alternatively, when a material other than glass is used, that its strength is equivalent to that of non-
toughened glass of 4,5 mm thickness;
e) that the material of the compass card will not distort;
f) that the moment of inertia of the directional system is approximately the same about all horizontal axes
passing through the bearing surface of the pivot jewel;
g) the vertical distance between the mid-plane of the magnets of the directional system and the inner gimbal
axis of the compass supplied;
h) the supporting force on the pivot at 20 °C;
i) that the inner and outer bearings of the gimbal rings are of the same type;
j) the length of bar magnets or diameter of ring magnet forming the directional system.
In order to check that the manufacturer's statement above has been fulfilled, sample checks may be carried
out.
B.2 Marking
Verify that the markings are as given in Table 11.
B.3 Compass and gimballing checks and tests
B.3.1 Construction and material
B.3.1.1 Condition of compass bowl
The compass shall be inspected to see that it is undamaged and mechanically perfect. The liquid shall be
colourless and free from turbidity and formation of flocks. There shall be no leaks. The paint, including that on
the compass card, shall be free from cracks and blisters.
B.3.1.2 Non-magnetic properties (type-test only)
Since the manufacturers have given a guarantee declaration, only sample checks are necessary.
Compass bowls and gimballing shall be tested to verify their non-magnetic properties.
B.3.1.3 Condition at high temperature
The compass shall be warmed slowly from room temperature to (60 ± 2) °C and maintained at this
temperature for at least 8 h. After this period, the compass shall not show any mechanical damage, leakage or
bubbles. The compass liquid and paint shall not show any deterioration, and the directional system shall not
be deformed. The compass shall operate satisfactorily, and shall meet the requirements of 4.1.6.
The directional system shall always be in contact with its pivot.
B.3.1.4 Condition at low temperature
Class A compasses shall be slowly cooled to (−30 ± 2) °C. Class B compasses shall be slowly cooled to
(−20 ± 2) °C. In either case they shall be maintained at this temperature for at least 8 h. After this period, the
compass shall not show any mechanical damage or deformation, leakage or bubbles. The liquid in the bowl
shall not freeze or discolour nor shall its ingredients separate. A formation of flocks or ice shall not have
occurred within the liquid and the directional system shall not be deformed. There shall be no deterioration in
the function of the compass, and it shall meet the requirements of 4.1.6.
The directional system shall always be in contact with its pivot.
B.3.1.5 Thickness of top and bottom glass covers (type-test only)
The thickness of top and bottom glass covers, measured by means of a micrometer, shall meet the
requirement of 4.1.5. As this requires opening the compass, it shall be done when the other examinations
have been carried out.
B.3.1.6 Transmitting system
A transmitting system shall not interfere with reading the card or taking bearings with an azimuth reading
device.
B.3.2 Compass gimballing
B.3.2.1 Plane of gimbal axes (type-test only)
Inspect the gimbal axes. They shall lie in one plane, within a tolerance of 1 mm, as specified 4.1.4.
This test may be carried out from a fixed horizontal reference plane by means of a suitable scale.
18 © ISO 2009 – All rights reserved

B.3.2.2 Angle of gimbal axes and intersection of vertical planes passing through them (type-test
only)
Measurement of the axes angles may be made by means of the test stand graduation, whereby first one then
the other gimbal axis is brought into the vertical plane of view passing through the graduation centre by
turning the compass support.
Determination of the intersection line may be carried out on a test stand by measuring the displacement of the
compass support in a direction perpendicular to either of the gimbal axes.
The test results shall meet the requirements of 4.1.4.
B.3.2.3 Freedom of movement within gimbal ring
When the gimbal ring is in the horizontal plane, the compass bowl shall freely revolve about the inner axis.
The measurement may be carried out by a clinometer placed on the top glass cover or verge ring. The test
result shall meet the requirement of 4.2.1.
B.3.2.4 Horizontal position
The compass bowl shall be balanced so that its verge ring or top glass cover settles in the horizontal plane
when the gimbal ring is fixed in a horizontal position. This shall be so whether the azimuth reading device or
other attachment or magnifier is in position or not.
Measurement shall be carried out by placing a spirit level of suitable sensitivity on the top glass or its verge
ring and the result shall meet the requirement of 4.1.7.
B.3.2.5 Friction of inner gimbal axis
When the gimbal ring is kept in the horizontal position and the compass bowl is inclined by ± 5°, it shall return
to within 2° of the horizontal plane.
The test may be carried out by means
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