Apparatus for measuring a measured variable, having - a first inductance (LP), - at least one measurement inductance (LS1, LS2, LS3) that is designed to sense the measured variable and that is coupled to the first inductance (LP), - a capacitance (CP) that is interconnected with the first inductance (LP) to form a parallel resonant circuit (P), and - an electronic control unit (MK), - wherein the electronic control unit (MK) is connected directly to the parallel resonant circuit (P) and is configured to excite the parallel resonant circuit (P) into oscillation at an excitation frequency that is derived from a clock of the electronic control unit (MK), - wherein the electronic control unit (MK) has at least one analog-to-digital converter having a signal input (P4, P5, P6) connected directly to the at least one measurement inductance (LS1, LS2, LS3) for picking up a signal, - wherein the electronic control unit (MK) has a distortion signal generator having a distortion signal output (P3, D), the distortion signal generator being designed to deliver a distortion signal at a distortion signal reference point (VRP), - wherein the distortion signal output (D) is coupled to the analog-to-digital converter exclusively by means of passive components, - wherein the electronic control unit (MK) is configured to measure the signal at intervals, a number of measured values being picked up within each interval, and - wherein the electronic control unit (MK) is configured to perform a frequency analysis of the measured values of a respective interval and to determine at least one characteristic value, indicating the measured variable, of the signal at an evaluation frequency. - a first inductance (LP), - at least one measurement inductance (LS1, LS2, LS3) that is designed to sense the measured variable and that is coupled to the first inductance (LP), - a capacitance (CP) that is interconnected with the first inductance (LP) to form a parallel resonant circuit (P), and - an electronic control unit (MK), - wherein the electronic control unit (MK) is connected directly to the parallel resonant circuit (P) and is configured to excite the parallel resonant circuit (P) into oscillation at an excitation frequency that is derived from a clock of the electronic control unit (MK), - wherein the electronic control unit (MK) has at least one analog-to-digital converter having a signal input (P4, P5, P6) connected directly to the at least one measurement inductance (LS1, LS2, LS3) for picking up a signal, - wherein the electronic control unit (MK) has a distortion signal generator having a distortion signal output (P3, D), the distortion signal generator being designed to deliver a distortion signal at a distortion signal reference point (VRP), - wherein the distortion signal output (D) is coupled to the analog-to-digital converter exclusively by means of passive components, - wherein the electronic control unit (MK) is configured to measure the signal at intervals, a number of measured values being picked up within each interval, and - wherein the electronic control unit (MK) is configured to perform a frequency analysis of the measured values of a respective interval and to determine at least one characteristic value, indicating the measured variable, of the signal at an evaluation frequency. <EOS>