Potentiometry measures the potential difference between two electrodes without drawing any significant current that would change the solution's composition through the electrochemical cell.

The cell uses an indicator electrode that exchanges electrons with the analyte solution and either a reference electrode in the same solution or another indicator electrode in a standard solution with a constant potential that acts as a reference electrode.

The half-cells are connected through a salt bridge, which is typically filled with an inert electrolyte.

Conventionally, the reference electrode is the anode or the left-hand electrode, and the indicator electrode is the cathode or the right-hand electrode.

The difference between the reduction potentials at the cathode and the anode gives the cell potential.

For accurate measurements, liquid junction potential E_j, which develops at interfaces between dissimilar electrolyte solutions, must be included in the cell potential.