Historical information

The heavy weight is pinned onto the map and the tracing arm is used to follow the boundary to be measured.
Reading from the digital scale the area in square centimetres could be measured.
Knowing the scale of the mapsheet the figure was converted to areas or hectares
Generally at least three measurements were taken to ensure accuracy and precision

Physical description

Planimeter used to measure areas from scale maps.

Inscriptions & markings

Kent Planitron UP103