ISO 22090-2:2014 pdf free
ISO 22090-2:2014 pdf free.Ships and marine technology一Transmitting heading devices (THDs)
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 1,0° 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.
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 5.3.
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 5.5.
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.This is repeated on the other side of the meridian and the mean is taken.
After indicating the magnetic heading on the display, when a few values of magnetic variations are manually or automatically input to the system, all the true headings indicated shall be within the accuracy of the requirement of 5.7. In the system containing a positioning system, after bringing the system to a position of which the magnetic field is not disturbed, turn the system so that the direction of the fore-and-aft mark from the centre aligns with a distant object of which the true bearing is known.The true heading indication coincidence shall also be within the accuracy of the requirement in 5.7.ISO 22090-2 pdf download.
