Devices for measuring planar area within a closed curved path

摘要

A device for measuring the movement of a movable means along a curved path comprises measuring means arranged to measure the movement of the movable means in terms of a series of increments corresponding to chords to the curved path of equal length, and counting means arranged to count the number of said increments. The movement may be in two or three dimensions. When the curved path is a two dimensional closed path, the area enclosed by the path can be measured.