- What is a graphic scale?
- What is a graphic scale for?
- Examples of graphic scale
- Graphic scale and numerical scale
We explain what a graphic scale is, what it is for and various examples. Also, the differences with a numerical scale.
A graphical scale shows the relationship between an actual distance and its representation.What is a graphic scale?
A graphic scale is a graduated straight line, divided into equal parts. The units of the scale represent the relationship between length of an object and the equivalent in units of He drew.
It is usually used in maps, nautical charts, plans and other forms of spatial representation with a unit-by-unit scale, that is, in which each unit drawn represents a set of real units of measurement. Not to be confused with Numerical scale, although both are cases of scale.
The graphical scale was used for the first time in the Pisan Letter of the late 13th century, a document found in Pisa, Italy. It is a map the seas Mediterranean, Black and part of the Atlantic Ocean. Its graphical scale appears as a circle whose radius is divided into three equal parts, each of which represents (not numerically) a distance from the scale map.
Saying design has since changed towards the shape of the straight line, generally located on the edges of maps vertically or horizontally, and known maritime as Trunk of leagues.
What is a graphic scale for?
The graphic scales give whoever consults a map information relative to the scale of your drawing. That is, it explains how the representation is linked to the real distances of the segment of the land surface which describes.
You can do it without the need to resort to numbers or numerical relationships, but rather through a graphic or visual convention, in accordance with the provisions of the various cartographic sciences.
Examples of graphic scale
Ancient maps began to have graphic scales from the 13th century.
Graphic scale and numerical scale
Unlike the graphical scale, which represents the scale by proportions visual, a numerical scale is one that fulfills the same function, that is, to inform us how the proportions of reality have been represented on a plane or document, but expresses the proportion through a set of numbers.
For example, a scale of 1:20 means that each unit in the representation is equivalent to 20 in real life, depending on the units in which they are expressed. Thus, it is common to see scales of 1 / 50,000 or 5/500, depending on how abstract the drawing is to be able to present huge objects or massive lengths, on a small screen or a paper cutout.
Both the numerical scale and the graphical scale are common in maps, plans, works of technical drawing, architectural projections, etc.