Abstract: A balance is an instrument for precise measurement of small weights or masses.Balances are classified based on their maximum weighing capacity, or load, and finest graduation, or division, of their weight-reading device.The single largest error in determining absolute amounts of mass is made when the effects of air buoyancy on the weighing object are neglected.A mechanical balance consists of a symmetric lever called a balance beam, two pans suspended from its ends, and a pivotal axis at its center.A single-pan substitution balance has one hanger assembly, incorporating both the load pan and a built-in set of weights on a holding rack.Electronic balances consist of a load-transfer mechanism, an electromechanical force transducer, and a signal processing component