Galvanostatic pulse technique with the current confinement guard ring: The laboratory and finite element analysis

Uncertainty of the polarised area of reinforcing steel is one of the major sources of error when measuring corrosion rate of steel in concrete. To overcome this problem, instruments equipped with the guard ring, aimed at limiting the polarised area, have been introduced and are available commercially. However, some limitations and disadvantages of the guard ring equipment have been reported [1], [2], [3], [4] and [5]. In addition, there are some doubts about the appropriate function of such instruments. In this paper, the function of the GalvaPulse™, one of the commercially developed equipment using guard ring, is analysed by using the Finite Element Analysis (FEA) technique and the results are compared with results obtained from the laboratory measurements.