ISO 22090-2-2014 pdf free download

ISO 22090-2-2014 pdf free download.Ships and marine technology Transmitting heading devices (THDs) Part 2:Geomagnetic principles
Navires et technologie maritime — Dispositifs de transmission de don nées de pilotage — Pci rtie 2: Principes géomagnétiques.
6.3 Fore-and-aft mark test
In magnetic-compass-type THDs, the examination can be carried out on a rotating test stand with the aid of a plumb line and with the compass in the binnacle.
In electromagnetic-compass-type TI-IDs, the examination shall be verified by visual inspection or electrical measurements.
The results shall fulfil the requirements specified in £3.
6.4 Static error test
6.4.1 Magnetic-compass-type THD
The static error applies to the compass without fluxgate sensors. The fluxgate of a THD shall be placed so that the influence on the card heading shall not exceed 1,00 on any heading.
The examination can be carried out on a compass test stand. After having brought the rotation centre of the compass card into the rotation axis of the test stand, the static error can be read at the card graduation by means of a telescope or any other appropriate means, when the vertical plane of the sight passing through the rotation axis has been aligned with the magnetic meridian in advance. This measurement shall be carried out on at least four equidistant headings.
The static error shall be within ± 1,0° (95 %)
If the test Is undertaken in the compass bowl, it should be noted that the resulting value includes the
deviation due to any magnetic material in the compass and/or in the fluxgate sensor.
6.4.2 Electromagnetic-compass-type THD
After having brought the fore-and-aft line of the sensor housing into the line passing through the centre of the test stand and the zero line orientated north, the static error can be read comparing the output heading with the rotation angle. This measurement shall be carried out on at least four equidistant headings. The test results shall conform with the requirements of the S.3.
6.5 Follow-up error test
Set up the magnetic sensor on a test platform, and rotate the platform at a rate of 20°/s. The readings of the heading output shall fulfil the requirements specified in &5,
6.6 Settling time test
The card, if fitted, is deflected 90°, held there for at least 10 s and then released. The time, in seconds, taken to return finally to within 1° of the magnetic meridian shall not exceed the value required in 5.6.ISO 22090-2-2014 pdf free download.