Equipment

The plane table basically consists of a simple drawing board mounted on a tripod same to a compass or a level. The drawing board commonly made from well seasoned teak or pine wood. The size can vary from 400 × 300 mm to 750 × 600 mm. Sometimes square boards of 500 × 500 mm or 600 × 600 mm are also used but size of square boards is rather uncommon.

Another significant constituent of plane table is a straight edge called Alidade. It is formed of a metal (brass or gunmetal) or seasoned wood about 500 mm long with a straight ruled edge which is bevelled. This edge is called as "fiducial" edge. It may be provided with sight vanes, at both ends in a plain alidade or (Figure 1(a)) with a telescope for better accuracy as shown in Figures 1. Within plain alidade one of the sight vanes is provided with a narrow slit and the other is provided with cross and stadia wires. Such as a level, two bubble tubes placed orthogonally are given for keeping the plane table horizontal. The bevelled edge is graduated so in which it can be used as a scale for plotting distances directly on the map.