Effect of ohmic drop on accuracy of reinforcement corrosion rate measured using different setups

High resistance offered by concrete to the current applied to polarize reinforcing bars embedded in concrete during measurement of reinforcement corrosion rate results in Ohmic drop, which causes inaccuracy in the measured value of the reinforcement corrosion rate. A study on accuracies of a simple developed setup and two other commercially available setups in measuring reinforcement corrosion rate using the linear polarization resistance method with and without Ohmic drop compensation is reported in this paper. The good correlation between electrochemically measured corrosion current density and gravimetrically measured percentage weight loss was taken as an indicator of accuracy of each setup. The developed setup was found to be most accurate in measuring corrosion rate without, as well as with, Ohmic drop compensation. Both commercial setups were found to have reasonably acceptable accuracy without Ohmic drop compensation; however, both were found with unacceptable accuracy with Ohmic drop compensation.