This method essentially consists of measurement of the ab- solute potential at the concrete surface with reference to a reference electrode. Corrosion being an electro-chemical phenomenon, the electrode potential of rebars with refer- ence to a standard electrode (known as half-cell) & a high- impedence voltmeter undergoes changes depending on corrosion activity.
Equipment: CANIN+ Corrosion Analyzing Instrument from M/s. Proceq, Switzerland