Measuring device for a figure

摘要

A measuring device for measuring the area of a closed curve is disclosed. A member is provided which moves freely along the centre of a vertical shaft in a condition in which it is fixed in the base. In order to measure the length, an actuating element slides in the horizontal direction through the member and is supported therein. A following (tracking) means for following the line of the figure engages with the front end of the actuating element. An angle of rotation of the member is measured in units of 0.072 DEG by an angle index plate which is fastened on a fixed shaft, while a moving distance is measured in units of 0.01 mm by a photosensor which is included in the member. While the following means is following the line of the figure on the basis of the central point of the member, the area of the figure is subdivided into a triangle whose one base is connected to that of the neighbouring triangle, which has the same angle. The device for measuring two bases of the triangle and the angle it encloses employs a sine rule (law). <IMAGE>