Scale (ratio)

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The white protective helmet (right) serves as a benchmark for the viewer and reveals the enormous size of the construction machine.

In technology , photography, cartography and model making, a scale is the relationship between the size shown (for example the length of the route) and the corresponding size in reality.


In some areas (mechanical engineering, electronics, macro photography) not only reductions but also enlargements are defined by specifying a scale. Here, for example, a scale of 2: 1 means that the construction drawing or the macro photo is twice as large as the real thing.

True to scale and scale factor

To scale or scale is a figure or a model, if any route appropriate to the length results in the representation in the original same ratio. The tolerance for graphics corresponds to the usual drawing accuracy of 0.2 mm. A photo or a hand sketch , for example, is not to scale . In technical parlance , "to scale" usually means a less precise representation than one that is "true to scale".

In geodesy , minor differences in the scale of surveying networks or earth models are often treated in the form of a mathematical scale factor (usually referred to as µ ). Since it is always very close to the value 1 , it is often set as µ = 1 + m and the very small value m is referred to as the scale correction .



In architecture, plans are used in a scale range from 1:10 (details) to 1: 1000 (overviews, external plans, site plans). However, some details are also drawn on a scale of 1: 1 to 1: 5 or, in extremely rare cases, even enlarged compared to reality.

In technical drawings, ISO 5455 gives suggestions for reductions and enlargements.


See also

Web links

Commons : yardsticks (ratio)  - collection of images, videos and audio files