The Principle And Function Of Magnetic Compass

The magnetic compass is a kind of pointing instrument made by the principle that the magnetic needle can point to the North (South) pole of the earth's magnetic field under the action of the geomagnetic force. As an important navigation instrument, magnetic compass has a very long history of installation and use in ocean ships. At present, although modern ships have been equipped with advanced navigation instruments such as gyroscope (gyrocompass), GPS, etc., but because modern magnetic compass has the characteristics of simple structure, reliable performance and independent of external conditions, it is still installed and used by marine ships as a necessary navigation instrument. The International Maritime Organization (IMO), classification society and ship inspection organizations of various countries have clearly stipulated that marine ships should be equipped with magnetic compass, and correct self deviation and self deviation table should be provided. 1. Magnetic compass classification A. according to whether there is liquid in the magnetic compass basin, there are liquid compass and dry compass. The compass of a liquid compass is suspended in a basin full of liquid. Due to the damping effect of liquid, the stability of the compass is better when the ship swings. In addition, due to the buoyancy of the liquid, the friction force between the supporting needle and the bearing of the compass can be reduced, thus improving the sensitivity of the compass basin. Our products are all liquid compass. b. According to the use of magnetic compass, there are standard compass and steering compass. The standard compass is generally vertical and installed on the top deck (compass deck) of the cab. Because of its high position, no shelter and little influence of ship's magnetism, it is used to observe the course, measure the target position and correct the steering compass, so it is called the standard compass. The steering compass is generally a bench type, which is installed in the cab to observe the course and steer. The company produces standard compasses and steering compasses of various models. c. According to the diameter of compass surface, common ones are 190mm, 165mm, 130mm and 100mm 2. Deviation and correction of magnetic compass The magnetization of the steel ship by the geomagnetic field will produce ship magnetism, which will affect the pointing accuracy of the magnetic compass, that is, the so-called "self deviation". This deviation can be corrected by the compass master. The magnetic compass produced by our company is equipped with an efficient self deviation correction device.