Abstract: A measuring device, such as a planimeter, having an increased measurable range for measuring a figure without increasing a length of the measuring device. The measurable range of a planimeter is based upon the a physical length of the planimeter. In order to increase the measurable range of the planimeter, the planimeter is provided with an operation control switch that functions to set a measurement mode of a computer associated with the planimeter to a suspend mode, temporarily halting a measurement operation, so that the planimeter can be shifted to another position. Thus, the measuring range of the planimeter is increased without increasing the physical length of the planimeter.

Abstract: A device for finding the centroid coordinates of a figure that can calculate the centroid from a single time measurement of the figure and display the calculated centroid of the figure. The measuring device comprises a main body having a roller capable of running in a single direction and a measuring lever pivotably supported by the main body so as to be rotatable right or left from the running direction of main body on a horizontal plane. In the measuring device, the main body has a display and a calculating circuit. The tracer of the measuring lever traces the contour of the figure to measure the coordinates, areas, and lengths of the figure. At the same time, the calculating circuit computes the geometrical moments of areas successively and sums the geometrical moments of the areas. Finally, the calculating circuit divides the summed geometrical moment of the areas by an area of the figure to obtain the coordinates of the centroid of the figure.