Planimeter

Planimeter with weight in a black velvet lined box.
Planimeters are used to calculate the exact area within an irregular shape. To use the planimeter, the weight is attached to the pointer arm to ensure that the planimeter stays in one place when it is being used. The tracer arm to which the tracer point is attached is used to trace clockwise around the edge of the shape that needs to be measured. The scales are set to 0 before use.

Object Details

ID: EQS0506
Collection: Testing, measuring and design instruments
Type: Planimeter
Display location: Not on display
Credit: National Maritime Museum, Greenwich, London
Measurements: Overall: 25 mm x 235 mm x 40 mm
Parts: Planimeter