Non-Destructive Electrical Methods (NDEM) using a four-electrode configuration are being developed for the corrosion monitoring of reinforced structures without altering their integrity [1]. Indeed, unlike conventional techniques based on a three-electrode configuration that requires a connection to the rebar, the measurement is performed directly on the concrete surface: two probes A and B inject a direct current while two other probes Mn and Nn measure an induced potential difference. However, despite the practical relevance of NDEM, their use is still at the margin. To promote such To promote such techniques, whose measured apparent resistivity ρapp depends on both concrete resistivity and corrosion rate, a better definition of their sensitivity domain is required, along with a detailed sensitivity analysis to concrete and rebar properties. This work reports a methodology designed to characterize the sensitivity domain for resolute corrosion rate determination from ρapp measurements using five Wenner-Schlumberger-Reciprocal (WSR) configuration (Figure 1). Specifically, in this work, models were computed to establish the sensitivity domain of the novel CorImager®- device developed by IRIS Instruments. The extensive modeling of synthetic data – considering several corrosion current densities jcorr, concrete resistivity ρc, effective depth ceff and rebar diameter Φ – provided abacus showing three distinct regions: two regions for extreme jcorr values in which ρapp is almost constant, and one region for intermediate jcorr values in which ρapp significantly decreases with increasing jcorr (Figure 2a). The latter region, defined as the sensitivity domain, depends on ρc, ceff, Φ, and the geometry of the chosen observation channel (Figure 2b). Within this domain, the amplitude of the sensitivity increases with the decrease in ceff or the increase in Φ, while increasing ρC by one order of magnitude shifts the domain of jcorr by one order of magnitude to lower values. The use of abacus allows quantifying the expected uncertainty on jcorr, according to the electronic noise of the monitoring device and to measurement uncertainties on ceff or Φ. The interpretation of overall results allow providing good practices to limit the impact of potential errors for corrosion diagnosis in field application. While developed specifically for the CorImager®-device in WSR configuration, the methodology can easily be adapted to any four-point configuration with apparent resistivity measurements. As a perspective, the data acquired with a multi-channel configuration open the way to inversion processes to determine the distribution of concrete resistivity and corrosion current density within the investigated volume.