What is a compass?
The compass is an instrument that is commonly used for orientation on a plane or map using the cardinal points. Although we can find four main cardinal points (north, south, east and west) the needle always points north, this is due to its operating principle that we will explain later.
Parts of the compass
This is practically one of the oldest instruments and therefore has undergone many improvements and modifications, but it always has some essential elements for its operation such as:
It serves to protect the internal mechanism and also to hold all other parts.
This ring is graduated in 360º and is able to rotate freely to achieve a more precise orientation, since the needle always points to the north and with this scale we can really know what degree to go.
Magnetic or magnetized needle
This needle is made up of two colors: one red and one blue or white, they are magnetized in such a way that the red color is always directed towards the geographical north and the other color towards the south.
This serves to prevent the needle from hitting the other parts and also to quickly stop the inertia movement that is generated with changes in orientation.
Direction line or arrow
This line is used to take it as a reference when we started our trip, so as not to have errors of perception either by moving the compass or not remembering the exact position in which the compass was calibrated at the beginning.
How does the compass work?
To understand how it works, we must know the basic concepts of magnetism: attraction and repulsion. These two concepts indicate that opposite poles attract and equal poles repel.
Once knowing about the poles, it is enough to know that the main compass needle is magnetized in such a way that the magnetic north of the earth and the compass repel each other and the south pole is north and the north pole is south.
Types of compasses
Although it is a fairly common object we can find some quite classic types and some more modern ones using technology.
This type has a transparent base and some other accessories such as: scalers, rulers in inches and cm, etc. because they are used together with topographic maps to be able to orient with too great an accuracy.
Although it seems a very simple compass it is not, since it has great power and usability. This type is mainly used in orientation contests because it allows you to have your hands free and has the ability to select the desired direction quickly with the help of a map.
Lensatic or walking
This type has a slightly more complex construction with a greater number of components and could resemble a military one, since it has components such as sights, lenses and reference points that work together to point in the right direction.
With the advancement of technology came compasses that work electronically, despite being the most modern have their disadvantages, and that is that they always depend on the amount of battery you have.
Within this category of compasses we can find all those that have a specific use such as: nautical, military, geological, forestry, etc.
Important Facts About Compasses
Some of the important data about these instruments that you have to know are:
They do not work at either the South Pole or the North Pole.
Any metallic object that is too close alters its operation.
Electronic devices also alter the compass operation.