Planimeter

1971/001

Amsler type planimeter

SKU: 1971/001 Categories: ,

Description

Amsler type polar planimeter with fixed index. Used for mechanically measuring the area of a plane surface on a map or plan.

The instrument is used as follows. The tracer point is moved to follow the boundary of a region to be measured. As the tracer point moves the wheel partially rolls and partially slides on the plan, and the integrating wheel records the distance the wheel travels perpendicular to the tracer arm. Once the tracer point completes its circumnavigation of the boundary, the number of turns of the wheel is proportional to the area of the region. When the instrument is calibrated appropriately, the area of the region can be read from the scale. On this instrument the number of turns of the measuring wheel cannot be reset to zero, so an initial record of the number of turns needs to be recorded and subtracted from the number of turns on completion of the circumnavigation.

Invented by J Amsler Professor of Mathematics Schaffhausen in 1854.

 

 

Additional information

Acquisition Number

1971/001

Item Type

Short Description

Amsler type planimeter

Manufactured by

Date of Manufacture

c. 1890

Sub-items

Case (damaged)

Supporting Items

None

Makers Number

11422

Marks

None

Dimensions (mm)

Case: 207 x 46 x 36

Donor

Date Donated

1971

Materials

Brass and Steel

Condition

Planimeter: good. Case: poor.

Display Location