Half-Cell Potentiometer Test
• This method may be used to indicate the corrosion activity associated with steel embedded in concrete.
• This method can be applied to members regardless of their size or the depth of concrete cover.
• This method can be used at the any time during the life of concrete member.
• The instrument measures the potential and the electrical resistance between the reinforcement and the surface to evaluate the corrosion activity as well as the actual condition of the cover layer during testing.
• The electrical activity of the steel reinforcement and the concrete leads them to be considered as one half of weak battery cell with the steel acting as one electrode and the concrete as the electrolyte.
• The name half-cell surveying derives from the fact that the one half of the battery cell is considered to be the steel reinforcing bar and the surrounding concrete.
• Then generally readings taken are at grid of 1 x 1 m for slabs, walls and at 0.5 m c/c for Column, beams.