Rebar Corrosion Voltmeter

Caltech Engineering Services offer Rebar Corrosion Tester is complete economical kit for identifying concrete rebar corrosion as per ASTM C876 or rebar corrosion detection. A STM C876 standard describes procedure for half cell potential of reinforced concrete structure. Accurate measurement of the rebar corrosion rate is necessary for estimating the remaining service life of concrete structures, scheduling repair or maintenance operation using half cell potential test procedure. This is the best corrosion measurement technique for rebar corrosion using half cell potential. Rebar Corrosion Tester detector kit includes half cell and voltmeter integrated with a high impedance and long earth cable and despensing damp sponge. When rebar corrosion voltmeter DV-05 is connected between the reinforcing steel, Cu-CuSO4 reference half cell electrode (Fontana-201F) and specially made highly electrical conductive despensing sponge on the concrete surface where a measurement can be made for the half-cell potential or half cell corrosion mapping. This test method applies to members regardless of their size or the depth of concrete cover over the reinforcing steel. Concrete cover in excess of 3 in. (75 mm) can result in an averaging of adjacent reinforcement corrosion potentials that can result in a loss of the ability to discriminate variation in relative corrosion activity. This gives measurement of the probability of corrosion activity. By testing at a fixed distance apart, a grid of half-cell potentials can be developed and areas delineated. This test method covers the estimation of the electrical half-cell potential of uncoated reinforcing steel in field and laboratory concrete, for the purpose of determining the corrosion activity of the reinforcing steel

By connecting a high impedance voltmeter between the reinforcing steel and a reference electrode placed on the concrete surface, a measurement can be made for the half cell potential at the location of the reference cell. This then is a measurement of the probability of corrosion activity in the steel in the vicinity of the reference cell. This is used to locate corroding steel reinforcement. When using Rebar Corrosion Kit, the potential measurements should be interpreted by engineers or technical specialists experienced in the fields of concrete materials and corrosion testing. It is often necessary to use other data such as chloride contents, depth of carbonation, delamination survey findings, rate of corrosion results, and environmental exposure conditions, in addition to corrosion potential measurements, to formulate conclusions concerning corrosion activity of embedded steel and its probable effect on the service life of a structure. 

The reference half cell is copper in a copper sulphate solution. By taking half cell potential measurements a fixed distance apart a grid of half cell potentials can be quickly made and thus areas delineated with a high probability of corrosion of the reinforcing steel. 

To analyze the results, the measurements made with rebar corrosion tester can be plotted on a grid and lines of equipotential contours drawn, highlighting areas of possible corrosion activity.