Types of Scale
a) Plane scale
- Most commonly used.
- Is used to represent two successive units, such as tenths, meters, decimeters, etc.
b) Diagonal Scale
- Using it, one can measure three dimensions such as ” units, tenths and hundredths”, i.e. metre, decimeter, and centimeters and so on.
c) Chord Scale
- Chord scale is used to measure an angle or to set-off an angle, and is marked either on rectangular protractor or on an ordinary box wood scale.
d) Vernier Scale
- Used for measuring a fractional part of graduated scale.
- Consists of approximating scales, one of them is fixed and is called the primary scale.
- The other is movable and is called the Vernier.
e) Shrunk Scale
- If a graphical scale is not drawn on the plan and the sheet on which the plan is drawn shrinks due to variations in the atmospheric conditions, it becomes essential to find the shrunk scale of the plan.
- The shrinkage ratio or shrinkage factor is equal to the ratio of the shrunk length to actual length.
- Once you find shrinkage factor, “Shrunk scale = shrinkage factor × original scale”