Proportion-dial

Used to transfer measurements from one scale to another. This capability is necessary when the drawing (or sketching) needs to be done on a larger or smaller scale, than the existing model. They can also be used to divide lines or circles into equal parts. A proportioned caliper consists of two legs of equal length, pointed at each end, and held together by a portable hinge. By changing the position of the hinge, the lengths of the legs on both sides of the hinge can be adjusted so that the ratio between them is equal to the ratio between the two leg developers. Therefore, the distance created between the two points of legs on one side will be proportional to the distance between the two points of the other legs, as a barrel Measure to each other.