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Figure 2.5 Magnetic testing principle of rebar
2. Single-electrode and double-electrode method of rust test
Single–electrode method (as shown in fig.2.6) applies testing principle
of half-cell self-potential method, the rebar under ionic environment
can be seen as an electrode, af ter corrosion, electrode potential
changed, therefore, potential reflec ts corrosion directly. As it is
well-known, battery consists of cathode and anode. Since rebar
electrode has only half feature of the battery, therefore it is called
half-cell.
Figure 2.6 Single-electrode method
Double-electrode method (as shown in fig.2.7) also applies
self-potential method. The difference only lies in that single-electrode
method applies to outside exposed structure of rebar end, while
double-electrode method applies to non-outside structure.
Operation manual of NOVASCAN-R800, R630, C310A
Novatest S.r.l.
www.novatest.it
