Why it is important to plantinize the electrodes of a conductivity cell before it is used for conductance measurments?

Platinized platinum electrode is the platinum electrode which is covered with compound called platinum black. This process of covering a platinum electrode with platinum black is called platinization of platinum.
Platinization increases the surface area of the electrode on which the hydrogen gas can be in contact with hydrogen ions(aqueous) so that reaction can proceed faster.