Inaccurate Orientation

While the table is set at new instrument station, the correct orientation is rather more significant than correct centering. A position of instrument station shall be accurately corresponding to its plotted position on the map. A survey details already plotted on the map from earlier instrument stations can synchronize along with details to be plotted on map from new instrument station only when the plane table is accurately centered and oriented within new position.

The correct orientation could be achieved through checking the orientation by two-point or three-point problem. Preferably the orientation of the table should be checked from as several stations as possible through sighting two distant and prominent reference stations that are already plotted on the map, thus eliminating the triangle of errors.

The orientation of the table should also be checked after observations, preferably after recording every observation to eliminate any chance rotation of table during the observation process because of improper clamping of table.