Measuring Metallic Corrosion with Half Cell Potential Test
When reinforcing steel corrodes inside concrete, an electro-chemical process occurs and its characteristics can be identified with a half-cell potential (HCP) measurement, also known as a ‘half cell potential test’. HCP measures metallic corrosion to determine the regions of potential corrosion and the risk it can impose on the structure. Date interpretation is nuanced and specific to particular sites, but generally a more negative potential means a risk of corrosion occurring in unsaturated marine exposed concrete. To conduct the test, an electrode is used to form one part of the bimetal cell, while the reinforcing steel within the concrete serves as the other half. Silver/silver chloride in a potassium chloride solution or a simple Copper/Copper Sulphate cell is the ideal reference electrode for use on-site. An electrode that is made of copper/copper sulphate is widely used, too. An advanced half cell potential meter is a great instrument to have for a more reliable way to ...