5.3 Accuracy under dynamic conditions
5.3.1 Settling time under dynamic conditions
When switched on in accordance with the manufacturer's instructions, the compass shall settle within 6 h when rolling and pitching with simple harmonic motion of any period between 6 s and 15 s, a maximum angle of 5°, and maximum horizontal acceleration of 0,22 m/s2.
5.3.2 Dynamic errors
The dynamic error amplitude shall be less than ±1.5°× secant latitude. The dynamic error frequency shall be less than 0,033 Hz equivalent to a period not shorter than 30 s if the amplitude of the dynamic error exceeds ±O.5°.
5.3.3 Performance under operational conditions
In latitudes of up to 70°N or S in ship operating within a latitude band of 10°;
- The residual steady state error, after correction for speed and course influences at a speed of 20 knots, shall not exceed ±0,35°× secant latitude; and
- The maximum error due to a rapid alteration of speed of 20 knots shall be kept to a minimum, and shall not exceed ±3°. The horizontal acceleration shall not exceed 2,0 m/s2; and
- The error due to a rapid alteration of course of 180°up to maximum rate of turn of 20°/s in heading up to a speed of 20 knots shall not exceed ±4,5°. The horizontal acceleration shall not exceed 2,0 m/s2.
5.3.4 Follow-up errors
The follow-up error for different rates of turn shall be:
- less than ±0.5°up to a rate of 10°/s; and
- less than ±1.5°up to a rate of between 10°/s and 20°/s.
6 Type tests
6.1 General
Where the Gyro-compass includes repeater compasses, at least one repeater compass shall be energized and aligned with the master compass at all times during the environmental tests. Each remaining repeater compass output shall be connected to a normal load, or to a suitable impedance representing a normal load, supplied by the manufacturer.
However, the associated repeater compass is not subject for this test.
The THD shall be tested for accuracy with the sensing part connected. If the sensing part is so designed that it is included in the transmitting part, the equipment shall be tested all parts.
6.2 Settling time test
The master compass shall be securely positioned on a nominally level and stationary base. It shall be energized from nominal value power supplies and started in accordance with the manufacturer's instructions from an initial heading error (to east) of 30｡?r more.
The settling time (see 3.10) shall meet the requirements of 5.2.l.
6.3 Static error (Settle point error) test
When the master compass has settled as defined in 3.10, the static error (see 3.7) shall conform to the requirements specified in 5.2.2.1.
6.4 Settle point heading repeat ability test
The master compass shall be started in accordance with the manufacturer's instructions from an initial heading error (to east) of 30｡?r more and shall be allowed to settle.
The settle point heading shall be determined as specified in 3.11. The master compass shall then be switched off for a period of not less than 12 h and not more than 7 days and then started again from an initial heading error (to west) of 30｡?r more and the settle point heading measured again.
The master compass shall then be switched off for a period of not less then 12 h and not more than 7 days and started again from an initial heading error (to east) of 30｡?r more and the settle point heading determined.
