Compass is divided into standard compass and rudder compass, which are installed in the cockpit. As one of the most important key parts of the ship's navigation, it determines the direction, speed and time of the ship's navigation, directly related to the safety of the ship. Therefore, to ensure the safety of compass and eliminate the interference of all systems, instruments and pipelines becomes the key technology of marine instruments. Now, more and more instruments in cockpit are required to provide the minimum safe distance from compass, so as to determine the installation position of the product in cockpit. Relevant international and domestic standards are also being formulated and enforced (such as iec60945).
The safe distance between the sample and compass is defined as the distance between the nearest point of the tested equipment unit and the compass center point or magnetometer, which is to ensure that the deviation of the standard compass does not exceed 5.4 ° / h. (H is the magnetic flux density of the horizontal direction at the test position) for the rudder compass, standby rudder compass and emergency compass, the deviation is required to be 18 ° / h.
The measurement method of the minimum safe distance of compass is to use the relationship between the intensity of the earth's magnetic field and the angle to convert the measurement of the angle into the measurement of the intensity of the magnetic field.
Radar compass safe distances are marked on both the transceiver plate and the manual.