Artificial crevice electrode

Pit and Crevice Growth Studies with Artificial Crevice Electrodes... 

Artificial crevice electrodes have been used to study the effect of dichromate on active dissolution of aluminum. In these experiments, 50 pm thick commercially pure A1 foils were placed between thin plastic sheets and mounted in epoxy. This assembly was fixed against a square cell that accommodated counter and reference electrodes and a trap that allowed for H2 gas collection. A schematic illustration of this cell and electrode is shown in Fig. 9 (36). Crevice corrosion growth experiments were conducted in aerated 0.1 M NaCl solution with additions of either 0.01 or 0.1 M Na2Cr207. Artificial crevice growth experiments were conducted under potentiostatic polarization at potentials ranging from 0 to... 

Therefore the reference electrode is placed with its Haber-Luggin capillary as close to the electrode surface as possible, thus measuring the electrode potential without large deviations due to a possible ohmic drop within the electrolyte. However, it should not get too close in order to avoid the formation of an artificial crevice. As a general rule, the distance should be two to three times the diameter of the capilleuy. The remaining ohmic drop AUa may be compensated for by up to more than 90% by a feedback loop of the potentiostat. 

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