Nicholls Colton Half cell potentential survey

Half-cell potential survey

The half-cell potential survey is used to provide information on the likelihood of corrosive activity to embedded reinforcement, but with only minimal damage to the overlying concrete.

Corrosion is an electrochemical process and the condition of the steel is assessed by measuring its half-cell potential.  An electrode (commonly copper-copper sulphate) forms one-half of an electrical cell, connecting through a voltmeter to reinforcement by means of a small intrusion through the concrete cover to form the other half.

Readings of half-cell potential (in –mV) are taken over a grid appropriate to the size of element being tested.  The more negative the reading obtained, the higher the likelihood of corrosion being present.

Results of half-cell potential surveys are presented in tabular form and also as a colour contour plot to allow easy identification of potentially problematic areas.

Testing is undertaken in accordance with a documented in-house procedure based on the requirements of ASTM C876-09 and is covered by our company *UKAS accreditation.