Scales used in Surveying | Engineering Surveys

Scales | Engineering Surveying

Scale is a fixed ratio that every distance on the plan bears with corresponding distance on the ground.

Scale can be represented by the following method

One centimetre on the plan represents some whole number of the metres on the ground.

1cm = 10m

This type of scale is called engineering scale.

1 unit of length on the plan represents some number of same units of length on the ground.

1/1000 etc…

This ratio of map distance to the corresponding ground distance independent of units of measurement is called Representative Factor (RF).

For example,

1cm = 50m

RF = 1/(50×100) = 1/5000

Above two types of scales are also known as numerical scales.

There are four main types of scales which are used for different purposes for measurements:

1. Plain Scale
2. Diagonal Scale
3. Vernier Scale
4. Scale of chords

We will discuss each of the scale type in detail in our succeeding articles…