Architect's scale

A scale ruler is a tool for measuring lengths and transferring measurements at a fixed ratio of length; two common examples are an architect's scale and engineer's scale. A scale ruler is a tool for measuring lengths and transferring measurements at a fixed ratio of length; two common examples are an architect's scale and engineer's scale. An architect's scale is a specialized ruler designed to facilitate the drafting and measuring of architectural drawings, such as floor plans and orthographic projections. In scientific and engineering terminology, a device to measure linear distance and create proportional linear measurements is called a scale. A device for drawing straight lines is a straight edge or ruler. In common usage both are referred to as a ruler. Because the scale of such drawings are often smaller than life-size, an architect's scale features multiple units of length and proportional length increments. For accuracy and longevity, the material used should be dimensionally stable and durable. Scales were traditionally made of wood, but today they are usually made of rigid plastic or aluminium. Architect's scales may be flat, with 4 scales, or have a symmetric 3-lobed cross-section, with 6 scales. In the United States, and prior to metrification in Britain, Canada and Australia, architect's scales are/were marked as a ratio of x inches-to-the-foot (typically written as x″=1′-0″). For example, one inch measured from a drawing with a scale of 'one-inch-to-the-foot' is equivalent to one foot in the real world (a scale of 1:12 measured from a drawing with a scale of 'two-inches-to-the-foot' is equivalent to six inches in the real world (a scale of 1:6). It is not to be confused with a true unitless ratio. A 1:5 architectural scale (inches to feet) would be a 1:60 unitless scale (inches to inches) since there are 60 inches in 5 feet.