Maker's Name: 
Koizumi, Japan
Where made: 
circa 1960

This Pole (or polar) Planimeter is able to mechanically measure the area of plane figures.

The pole weight is placed on the desk. The pole arm connects the pole weight to the carriage while the tracer point is connected to the carriage by the tracer arm. This causes the carriage to move on a circular path, regardless of the shape the tracer point follows. The area of the figure is measured by tracing the outline of the figure with the tracer arm, and is determined by how much the measurement wheel rotated.


  • adjustable tracer arm (made of stainless steel)
    can be easily optimized for either measuring range or resolution by adjusting the adjustment screw.
    scaled in cm.
    marked: #2847
    attached: measuring wheel carriage
  • pole weight (made of Diecast alloy painted green)
    marked: #2847
  • measuring wheel carriage with arbitrary scale.
  • push button to zero the measuring mechanism.
  • checking ruler (made of stainless stell) marked: 10 sq.
  • hand magnifier (made of plastic, black)
  • extra pin for the pole weight.

Comes in a metal case covered by black vinyl and lock, packed in a protecting foam.

Instrumental Accuracy : +/- 0.2%

Max. Resolution: 0.009
The Range: 9 x 19 in
                   25 x 50 cm


  2. Planimeters (
  3. The Pole Planimeter (