ISO 20672:2022 pdf download – Ships and marine technology — Rate of turn indicators.
4.4 Illumination and lighting The illumination and lighting of the indicator shall be arranged in order not to hinder an operator’s vision at night and in order to make the scale, pointer and letters as equally visible as possible even in dim light or darkness. 4.5 Type of indicator The rate of turn indicator shall be an analogue-type indicator. A digital-type indicator may additionally be used, if fitted. If a display is used for presentation, the equipment shall comply with MSC.191(79), as amended by MSC.466(101), and IEC 62288. 4.6 Alert If the equipment is capable of raising an alert, it shall comply with MSC.302(87), IEC 62923-1 and IEC 62923-2. 5 Performance requirements 5.1 Accuracy 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 ± 1° and period of up to 20 seconds shall not change the mean value of the indicated rate of turn by more than ± 0,5° per minute. c) [IMO Resolution A.526(13), 2.5.3] A rate of turn indicator shall meet these accuracy requirements at all 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 a time constant which may be varied during operation in the range zero to at least 10 seconds. 5.2 Operation a) [IMO Resolution A.526(13), 3.1] A rate of turn indicator shall be ready for operation and comply with this 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 of turn 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 the operator to verify that it is operating. 5.3 Insulation resistance and high voltage When insulation resistance and high voltage tests are to be carried out, IEC 60092-504 may be applied.
6 Methods of testing and required test results 6.1 Construction The construction of the rate of turn indicator shall comply with the requirements specified in Clause 4. If a display is used for presentation, confirm using documented evidence that the equipment complies with IEC 62288. 6.2 Environmental tests Unless otherwise stated in this document, all the tests shall be carried out according to the requirements of IEC 60945. The manufacturer shall determine which components of the rate of turn indicators shall be protected or exposed, as defined in IEC 60945.
ISO 20672:2022 pdf download – Ships and marine technology — Rate of turn indicators
