ISO 25862:2019

INTERNATIONAL ISO
STANDARD 25862
Second edition
2019-07
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 2019
© ISO 2019
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Published in Switzerland
ii © ISO 2019 – All rights reserved

Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Magnetic compasses . 2
4.1 General . 2
4.1.1 Class A magnetic compass . 2
4.1.2 Class B magnetic compass . 2
4.2 Construction and materials . 3
4.2.1 Magnetic material . 3
4.2.2 Lubber mark . 3
4.2.3 Position of the card (class A only) . 3
4.2.4 Angle of gimbal axes and intersection of vertical planes passing through them . 3
4.2.5 Thickness of the top glass cover (class A only) . 3
4.2.6 Constructional condition within the temperature range . 3
4.2.7 Horizontal position . 4
4.3 Mounting . 4
4.3.1 Tilt of supporting device . 4
4.3.2 Freedom of the compass card with no supporting gimbal . 4
4.4 Directional system . 4
4.4.1 Moment of inertia . 4
4.4.2 Suspension (class A only) . 4
4.4.3 Magnetic moment . 4
4.4.4 Settling time . 5
4.4.5 Tilt of the directional system with regard to the vertical field (class A only) . 5
4.4.6 Supporting force (class A only) . 6
4.5 Compass card . 6
4.5.1 Graduation . 6
4.5.2 Diameter of the card . 6
4.5.3 Readability . 6
4.5.4 Bearing compasses . 7
4.6 Accuracy . 7
4.6.1 Directional error . 7
4.6.2 Error of lubber marks . . 7
4.6.3 Error due to friction . 7
4.6.4 Swirl error . 8
4.6.5 Induction error (class A only) . 8
4.6.6 Mounting error of azimuth reading device . 8
4.6.7 Error due to eccentricity of the verge ring (class A only). 8
4.7 Environmental conditions tests of magnetic compasses (class A only) . 8
5 Binnacles . 9
5.1 General . 9
5.2 Binnacle type A1 . 9
5.2.1 General. 9
5.2.2 Construction and materials . 9
5.2.3 Provision for correction of deviation (if combined with class B compasses) . 9
5.2.4 Accuracy of fore and aft marks .11
5.2.5 Illumination .11
5.2.6 Environmental conditions requirements (class A only) .11
5.3 Binnacle type A2 .11
5.3.1 General.11
5.3.2 Construction and materials .11
5.3.3 Provision for correction of deviation .11
5.3.4 Accuracy of fore and aft marks .12
5.3.5 Illumination .13
5.3.6 Environmental conditions requirements (class A only) .13
6 Azimuth reading devices .13
6.1 General .13
6.2 Azimuth sight .13
6.3 Azimuth reading devices with vanes .13
6.4 Level .13
7 Marking .13
8 Designation .14
Annex A (normative) Testing and certification of marine magnetic compasses, binnacles
and azimuth reading devices — General requirements .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
Bibliography .49
iv © ISO 2019 – 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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the diff
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