Compass - Modern navigational compasses

A compass (or mariner's compass) is a navigational instrument for finding directions on the earth. It consists of a magnetised pointer free to align itself accurately with Earth's magnetic field. A compass provides a known reference direction which is of great assistance in navigation. The cardinal points are north, south, east and west. A compass can be used in conjunction with a clock and a sextant to provide a very accurate navigation capability. This device greatly improved maritime tr ...

Including:

• Compass - History of the navigational compass
• Compass - Construction of a simple compass
• Compass - Modern navigational compasses
• Compass - Solid state compasses
• Compass - Compass correction
• Compass - Points of the compass

Read more here: » Compass: Encyclopedia - Compass

Modern navigational compasses hold a magnetized needle inside a fluid-filled capsule; the fluid causes the needle to stop quickly rather than oscillate back and forth around magnetic north. Other features common on modern handheld compasses are a baseplate with rulings for measuring distances on maps, a rotating bezel for measuring bearings of distant objects, and a sighting mirror that lets the user see both ...

See also:

Compass, Compass - History of the navigational compass, Compass - Construction of a simple compass, Compass - Modern navigational compasses, Compass - Solid state compasses, Compass - Compass correction, Compass - Points of the compass

Read more here: » Compass: Encyclopedia II - Compass - Modern navigational compasses

Compasses were initially used in feng shui in ancient China. The first known use of Earth's magnetic field in this way occurred in ancient China as a spectacle. Arrows were cast similarly to dice. These magnetised arrows aligned themselves pointing north, impressing the audience. The earliest record of use of magnetic lodestone as a direction point was in a 4th century Chinese book: "Book of the Devil Valley Master" "Dream Pool Essays" written by Song Dynasty scholar Shen Kua in AD 1086 contained a detailed description of how geomance ...

See also:

Compass, Compass - History of the navigational compass, Compass - Construction of a simple compass, Compass - Modern navigational compasses, Compass - Solid state compasses, Compass - Compass correction, Compass - Points of the compass

Read more here: » Compass: Encyclopedia II - Compass - History of the navigational compass

A ship's compass must be corrected for errors, called compass deviation, caused by iron and steel in its structure and equipment. The ship is swung, that is rotated about a fixed point while its heading is noted by alignment with fixed points on the shore. A compass deviation card is prepared so that the navigator can convert between compass and magnetic headings. The compass can be corrected in three ways. First the lubber line can be adjusted so that it is aligned with the direction in which the ship travels, then the effects of per ...

See also:

Compass, Compass - History of the navigational compass, Compass - Construction of a simple compass, Compass - Modern navigational compasses, Compass - Solid state compasses, Compass - Compass correction, Compass - Points of the compass

Read more here: » Compass: Encyclopedia II - Compass - Compass correction

A magnetic rod is required. This can be created by aligning an iron or steel rod with Earth's magnetic field and then tempering or striking it. However, this method produces only a weak magnet so other methods are preferred. This magnetised rod (or magnetic needle) is then placed on a low friction surface to allow it to freely pivot to align itself with the magnetic field. It is then labeled so the user can distinguish the north-pointing from the south-pointing end; in modern convention the north end ...

See also:

Compass, Compass - History of the navigational compass, Compass - Construction of a simple compass, Compass - Modern navigational compasses, Compass - Solid state compasses, Compass - Compass correction, Compass - Points of the compass

Read more here: » Compass: Encyclopedia II - Compass - Construction of a simple compass

Small compasses found in clocks and other electronic gear are Solid-state electronics usually built out of two or three magnetic field sensors that provide data for a microprocessor. Using Trigonometry the correct heading relative to the compass is calculated. Often, the device is a discrete component which outputs either a digital or analog signal proportional to its orientation. This signal is interpreted by a controller or microprocessor and used either internally, or sent to a display unit. An example implementation, including par ...

See also:

Compass, Compass - History of the navigational compass, Compass - Construction of a simple compass, Compass - Modern navigational compasses, Compass - Solid state compasses, Compass - Compass correction, Compass - Points of the compass

Read more here: » Compass: Encyclopedia II - Compass - Solid state compasses