Description

Rebar probes, Model CP-REB, and steel probes, Model CP-STL, are usually installed the same distance below the surface as the rebar being monitored. They are often used in conjunction with an Ag/AgCl reference electrode such as the Model CB-AGG for linear polarization resistance measurements of corrosion rate. In this application, the rebar probe is the working electrode while the rebar net is the counter electrode. By periodically monitoring corrosion rate, the efficacy of sealers, membranes and inhibitors can be verified.

A graphite probe is not an equivalent substitute for an Ag/AgCl reference electrode such as the EDI Model CB-AGG because the rest potential of graphite is dependent upon the oxygen level in the surrounding concrete. Consequently, its potential can show long term variations of 150 mV or more. Graphite probes, Model CP-GRA, are suitable as a short term stable reference point for measurements such as E log I or potential decay. Model CM-AGC Ag/AgCl probe can also be used for the same applications where enhanced long-term stability is required but the absolute accuracy of a silver/silver chloride reference electrode is not needed.