ISO 22090-1:2014 pdf free
ISO 22090-1:2014 pdf free.Ships and marine technology一Transmitting heading devices (THDs)
The master compass shall be started in accordance with the manufacturer’s instructions from an initial heading error (to east) of 30° or 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 d, and then started again from an initial heading error (to west) of 30° or more and the settle point heading measured again.
The master compass shall then be switched off for a period of not less than 12 h and not more than 7d and started again from an initial heading error (to east) of 30° or more and the settle point heading determined. The three values of settle point heading obtained shall be recorded and the difference between any two shall not exceed 0,35°×secant latitude.
NOTE If this test follows the test described in 6.3, the “settle” obtained in 6.3 may be used as the first value required by this repeatability test provided that the second “settle” follows a switch-off period of not less than 12 h and not more than 7 d.
The supply voltage shall be set to 10 % above the nominal value for 3 h, during which time the THD heading shall be recorded at 20 min intervals. The supply voltage shall then be set to a value 10 % below nominal for 3 h, and the THD heading again recorded at 20 min intervals. None of the recorded headings shall depart from the original datum by more than 1,5°×secant latitude.
In the case of AC supply, the frequency shall be set to 5 % above the nominal value for 3 h, during which time the THD heading shall be recorded at 20 min intervals. The supply frequency shall then be set to a value 5 % below nominal for 3 h and the THD heading again recorded at 20 min intervals. None of the recorded headings shall depart from the original datum by more than 1,5°×secant latitude. ISO 22090-1 pdf free download.
