A beam balance is a simple device used to measure the mass of an object. It consists of a horizontal beam that is supported at its center, allowing it to pivot. On one side of the beam, the object to be weighed is placed, while the other side holds standard weights. When the beam is balanced, the mass of the object can be determined by comparing it to the known weights. Beam balances operate on the principle of equilibrium, where the forces acting on both sides are equal. They are commonly used in laboratories and educational settings to teach the concepts of mass and weight. Unlike digital scales, beam balances do not require electricity and can provide accurate measurements when properly calibrated.