此款求積儀由美國人Lucian Sheldon於1911年發明，用於測量或積分其坐標不與高度或長度成比例的曲線。例如，在記錄流體流量的實驗圖表中，橫軸為時間，縱軸為流體流速，使用此求積儀對圖表上的曲線進行量測可得到流量。

This planimeter was invented by Lucian Sheldon in 1911 and is used to measure or integrate curves whose coordinates are not proportional to their height or length, for example, for a flow rate chart where the horizontal axis represents time and the vertical axis represents fluid flow rate.