inductive sensor unit for detecting a spacing from a metallic object, comprising - a sensor coil , wherein the sensor coil has an inductance (L) and an active resistance (RS), and the sensor coil can be acted on by an excitation signal, - a transistor (O1), - a resistance (R3), - an evaluating unit for determining the spacing, wherein the evaluating unit is arranged for the purpose of providing an evaluation signal in dependence on the determination, - a switching unit for determining an actual value (I) of the inductance (L) of the sensor coil and/or an actual value (I) of the active resistance (R S ) of the sensor coil and/or a variable having a functional correlationship with the actual value (I) of the inductance (L) and/or with the actual value (I) of the active resistance (R S ) and derived from one or more of the actual values (I), wherein - the sensor coil is connectible by way of the transistor (Q1) and the resistance (R3) with a voltage source (V+) arranged to provide an excitation signal, wherein a control signal (V Puls ) can be fed to the control electrode of the transistor (Q1), - the switching unit comprises a computing unit arranged to receive scanning values of a voltage (U 2 ) of the sensor coil and a voltage (U 1 ) from the resistance (R3), - the computing unit is configured to determine actual values (I) of the active resistance (R S ) and/or the inductance (L) and/or the derived variable from the time plot of the coil voltage at a plurality of time intervals and - the computing unit comprises an interface to provide by means of the interface the actual value (I) of the active resistance and/or the active value (I) of the inductance (L) and/or the derived variable additionally to the evaluation signal. - a sensor coil , wherein the sensor coil has an inductance (L) and an active resistance (RS), and the sensor coil can be acted on by an excitation signal, - a transistor (O1), - a resistance (R3), - an evaluating unit for determining the spacing, wherein the evaluating unit is arranged for the purpose of providing an evaluation signal in dependence on the determination, - a switching unit for determining an actual value (I) of the inductance (L) of the sensor coil and/or an actual value (I) of the active resistance (R S ) of the sensor coil and/or a variable having a functional correlationship with the actual value (I) of the inductance (L) and/or with the actual value (I) of the active resistance (R S ) and derived from one or more of the actual values (I), wherein - the sensor coil is connectible by way of the transistor (Q1) and the resistance (R3) with a voltage source (V+) arranged to provide an excitation signal, wherein a control signal (V Puls ) can be fed to the control electrode of the transistor (Q1), - the switching unit comprises a computing unit arranged to receive scanning values of a voltage (U 2 ) of the sensor coil and a voltage (U 1 ) from the resistance (R3), - the computing unit is configured to determine actual values (I) of the active resistance (R S ) and/or the inductance (L) and/or the derived variable from the time plot of the coil voltage at a plurality of time intervals and - the computing unit comprises an interface to provide by means of the interface the actual value (I) of the active resistance and/or the active value (I) of the inductance (L) and/or the derived variable additionally to the evaluation signal. <EOS>