ISO 14227 pdf download.Small craft — Magnetic compasses
1 Scope
This International Standard specifies the general requirements for the construction as well as the performance of type tests of magnetic compasses on board small craft of hull length up to 24 m. It refers to liquid magnetic compasses, which can be inspected (e.g. not sealed), either equipped with a direct reading system, or of the reflecting/projecting type. This International Standard also covers magnetic compasses (3.1) not supported on gimbals. The requirements relating to gimbals do not refer to such magnetic compasses. This International Standard does not cover – dry card compasses, or – types of compasses designed on principles different from those stated above or not complying with the description given in this clause (e.g. transmitting compasses).
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 1069:1973, Magnetic compasses and binnacles for sea navigation — Vocabulary IEC 60721-3-6:1987, Classification of environmental conditions. Part 3: Classification of groups of environmental parameters and their severities. Section 6: Ship environment IEC 60721-3-6, Amendment 1, 1991 IEC 60721-3-6, Amendment 2, 1996
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions of ISO 1069 and the following apply. 3.1 magnetic compass instrument consisting of a directional system supported on a pivot inside a bowl which is completely filled with liquid and which may be supported on gimbals 3.2 gimbals devices permitting movements regarding the longitudinal and transversal axes of the craft so as to allow the directional system to seek a horizontal position regardless of the motion of the craft 3.3 static stability of the card condition allowing the card to stay horizontally in its balance position 3.4 mechanical stability of the card condition permitting to reduce to a minimum the angular acceleration that the card can attain when under rolling, pitching or vibration 3.5 magnetic stability of the card condition permitting to call back the magnetic axis of the card to the magnetic meridian when moved away, forced by the horizontal component H of the total magnetic field of the earth 3.6 directional error algebric sum of the collimation error, eccentricity error and graduation error 3.7 horizontal component H value of the horizontal component of the total magnetic field of the earth at the testing site 3.8 vertical component Z value of the vertical component of the local total magnetic field of the earth 3.9 lubber error difference in degrees between the compass lubber mark and the vertical plane passing through the external gimbal axis 3.10 friction error difference in degrees between the initial value and that obtained after the deflection of a small angle 3.11 swirl error d ifference in degrees between the heading reading after a complete rotation of the bowl at a uniform speed of 1,5 °/s and that carried out at rest at the beginning of the test
5 Magnetic compasses
5.1 Construction and material.5.2.2 Within the temperature range of − 30 °C to + 60 °C, the liquid in the compass bowl shall remain clear and free from bubbles, and neither emulsify nor freeze. There shall be no inward leak of air, nor outward leak of liquid. 5.2.3 The upper glass (and lower glass, if this exists) of the compass bowl shall have suitable characteristics and thickness. The balance of the compass bowl shall not be disturbed by any magnifying device or by any azimuth reading device provided for use with the compass. 5.2.4 The compass bowl shall be designed so that sufficient mounting surface and free space for the installation of a magnetic sonde is provided, if required by the yard/customer.