Half Cell Potential Measurement
Application
The main application is to estimate the probability of corrosion of the steel reinforcement embedded in concrete members.
The Digital Half Cell
Corrosion of the rebars is an electrochemical process which involves anodic (corroding) and cathodic (passive) areas of the metal.
By measuring concrete-surface electrical potentials relative to a standard reference electrode, areas where corrosion is present can be determined.
It is equipped with a detachable silver/silver chloride electrode, and measurements are automatically converted to copper/copper sulphate equivalent potentials and displayed on the digital meter.
The electrolyte (i.e. the saturated copper sulphate solution) and the conductor (i.e. the copper rod) are made into a probe which can be held against the concrete surface.
This probe is called the half-cell, the other half of the cell being the reinforcement and the concrete. Together the two half-cells form a complete electrical cell that generates a potential that can be measured with a high impedance millivoltmeter.