A plain scale can show a maximum of two units: a unit and its sub-division.
Understanding Plain Scales
A plain scale is a graphical representation used in engineering drawings to measure distances accurately. It allows for the representation of two units. For example, a plain scale might show meters and decimeters, or feet and inches.
How Plain Scales Work
Plain scales operate by dividing a line into primary divisions, each representing a unit (e.g., meters). One of these primary divisions is further subdivided into smaller units (e.g., decimeters). This allows for measurements to be taken with greater precision than just using whole units.
Example
Consider a scale where 1 cm on the drawing represents 1 meter in reality. If you want to measure up to 6 meters, you would draw a line representing 6 cm (since 1 cm = 1 m). You would then divide this line into 6 primary divisions, each representing 1 meter. One of these meter divisions would then be subdivided into 10 decimeters, allowing you to measure distances like 3.4 meters accurately.
Summary
Plain scales are designed to represent a unit and its sub-division, enabling more precise measurements than using just whole units. They can represent, at most, two levels of units.
