Spring Balance

Spring Balance is a weighing machine dependent for its action upon the fact that the extension of a spiral spring is proportional to the applied force. In its simplest form it is merely such a spring flexed at its upper end and provided at its lower end with a hook or pan to hold the article to be weighed, and an index moving over a graduated scale. In order to obtain greater sensitiveness, a rack and pinion or their equivalent is sometimes used to cause the movement of the lower end of the spring to result in the rotation of a pointer over a graduated dial. In some balances the weight is measured by the amount of bending produced in a flat curved spring, to one end of which a pointer is fixed.