What is laboratory balances

An analytical balance is an instrument used to measure mass to a very high degree of precision. The weighing pan(s) of a high accuracy (0.1 mg or better) analytical balance are inside a see-through enclosure with doors so dust does not collect and so any air currents in the room do not affect the delicate balance. Also, the sample must be at room temperature to prevent natural convection from forming air currents inside the enclosure, affecting the weighing.

Very precise measurements are achieved by ensuring that the fulcrum of the beam is friction-free (a knife edge is the traditional solution), by attaching a pointer to the beam, which amplifies any deviation from a balance position; and finally by using the lever principle, which allows fractional weights to be applied by movement of a small weight along the measuring arm of the beam.