Analytical balance as the name implies is an instrument use in weighing substance in the laboratory. Instrument is basically a two pan balance.
It has a simple operation by which a set of Known weight is added in one Pan while the other pan is balanced by the substance being a weights. This type of balance is fast fading away.
A modifications of the balance described above is a single pan balance.
Attached to one end of the balance is a beam with a weighing scale on it.
Before Weighing a substance, the scale is set to zero with the aid of a knob at the other end of the beam. A substance is weight by moving the scale on the beam to achieve equilibrium. This balance take a maximum load of about 200 g with the sensitivity of 1 mg.
Reference
Medical Laboratory Science theory and Practice, page 18.
J. Ochei and A Kolhatkar. publish in 2000