Inductive sensor device for determining a longitudinal position of a moveable object along a sensitive axis of the sensor device and method for operating a sensor device of this kind

A method for operating an inductive sensor device (10) for determining a longitudinal position (P) of an object (11) which is moveable at a distance from an end face (12) of the sensor device (10) and which is at least partially electrically conductive and/or magnetically polarizable, along a sensitive axis (S1) of the sensor device (10), wherein the method comprises:

• producing an alternating magnetic field of a substantially planar exciting coil (16) of a coil arrangement (14) of the sensor device (10) for inducing eddy currents and/or magnetic polarization in the object (11),
• determining, by means of sensor electronics (30) of the sensor device (10), at least one parameter (DSS) of an electrical signal of the exciting coil (16), which is altered by an inductive backward effect of the object (11), and at least one parameter (PSS) of a voltage induced in a first receiving coil (18;
• 18a-18b) of the coil arrangement (14) owing to the inductive backward effect of the object (16), wherein the first receiving coil (18;
• 18a-18b) is of substantially planar configuration and is arranged substantially parallel to and overlapping the exciting coil (16), wherein the exciting coil (16) and the first receiving coil (18;
• 18a-18b) are arranged substantially parallel to the end face (12) of the sensor device (10), and
• determining, by means of the sensor electronics (30), the longitudinal position (P) based on the at least one parameter (DSS) of the electrical signal of the exciting coil (16) and the at least one parameter (PSS) of the induced voltage of the first receiving coil (18;
• 18a, 18b).