ISO 20672 pdf download Ships and marine technology — Rate of turn indicators
This document specifies the construction, performance requirements, methods of testing and requiredtest results for the rate of turn indicators required by Clause 2.9.1, Regulation 19, chapter V,SOLAS 1974(as amended, 2000).
lt is based upon the requirements of lMO Resolution A.526(13), and is also associated with lMOResolution A.694 (17) and IEC60945.
Where a requirement in this document is different from that in IEC 60945, the requirement in thisdocument takes precedence.
NOTE All requirements that are extracted from the recommendations of lMo Resolution A.526(13)on performance standards for rate of turn indicators are printed in italics and the resolution and paragraphnumbers are indicated in brackets.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references, only the edition cited applies.Forundated references, the latest edition of the referenced document (including any amendments) applies.IEC 60945,Marine navigation and radiocommunication equipment and systems —General requirements—Methods of testing and required test results
IMO Resolution A.526(13), Performance standards for rate-of-turn indicators
3Terms and definitions
For the purposes of this document, the following terms and definitions apply.
lSO and IEC maintain terminology databases for use in standardization at the following addresses:— ISO online browsing platform: available at https://www.iso.org/obp
—IEC Electropedia: available at https:.//www.electropedia.org/
rate of turn indicator
indicator capable of indicating rates of turn in degrees per minute to starboard and to port of the shipto which it is fitted
Note 1 to entry: A rate of turn indicator may be self-contained; alternatively it may form part of, or deriveinformation from,any other appropriate equipment.
[SOURCE: IMO Resolution A.526(13),2.1 and 2.2, modified — in the definition, added ” in degrees perminute”.]
indicator that shows the rate of turn in a continuous way, such as by means of an arrow pointer and agraduated scale
4.4Illumination and lighting
The illumination and lighting of the indicator shall be arranged in order not to hinder an operator’svision at night and in order to make the scale, pointer and letters as equally visible as possible even indim light or darkness.
4.5Type of indicator
The rate of turn indicator shall be an analogue-type indicator.A digital-type indicator may additionallybe used, if fitted.
lf a display is used for presentation, the equipment shall comply with MSC.191(79), as amended byMSC.466[101), and IEC 62288.
lf the equipment is capable of raising an alert, it shall comply with MSC.302(87),IEC 62923-1 andIEC62923-2.
a)[IMO Resolution A.526(13),2.5.1] The indicated rate of turn shall not deviate from the actual rate of
turn of the ship by more than 0,5° per minute plus 5 per cent of the indicated rate of turn of the ship.These values include the influence of earth rate.
b)[IMO Resolution A.526(13), 2.5.2] Periodic rolling motion of the ship with an amplitude of ± 5° and
period of up to 25 seconds and periodic pitching motion with an amplitude of t 1° and period of upto 20 seconds shall not change the mean value of the indicated rate of turn by more than ± 0,5° perminute.
)[IMO Resolution A.526(13),2.5.3] A rate of turn indicator shall meet these accuracy requirements atall ship speeds up to 30 knots.
d)[IMO Resolution A.526(13),2.4.3]The damping of the rate of turn indicators shall be provided with atime constant which may be varied during operation in the range zero to at least 10 seconds.
a)[IMO Resolution A.526(13),3.1] A rate of turn indicator shall be ready for operation and comply withthis document within 4 minutes of being switched on.
b)[IMO Resolution A.526(13), 3.2] The design shall be such that whether operating or not the rate ofturn indicator will not degrade the performance of any other equipment to which it is connected.
c)[IMO Resolution A.526(13), 3.3] The rate of turn indicator shall include a means of enabling theoperator to verify that it is operating.
5.3Insulation resistance and high voltage
When insulation resistance and high voltage tests are to be carried out, IEC 60092-504 may be applied.