A sensor system including devices and methods for determining the concentration of an analyte in a sample is described. Input signals including amperometric and voltammetric duty cycles of excitations and relaxations may provide a shorter analysis time and/or improve the accuracy and/or precision of the analysis. The disclosed system may reduce analysis errors, thus improving measurement performance, by adjusting the potential and/or scan rate in response to output currents obtained from voltammetric scans. The disclosed system also may determine the concentration of more than one ionizable species in the sample by adjusting the potential and/or scan rate in response to output currents obtained from voltammetric scans. The multiple, determined concentrations may be used to determine the concentration of multiple analytes or to correct the concentration determined for an analyte, thus improving the measurement performance of the system.