Current collector and method for operation

A method for operating a current collector (10, 33), which is disposed on a roof (11, 34) of a rail vehicle (31), for transferring energy from a contact line (16, 25, 35) of an overhead contact line to the rail vehicle, the current collector comprising a positioning device (13, 56) having a sliding piece (14, 17, 27) disposed thereon, the positioning device moving the sliding piece relative to the contact line and pressing it against the contact line in a sliding contact position using a pressing force in order to establish a sliding contact, the pressing force being produced on the sliding piece by means of a drive mechanism and a spring mechanism of the positioning device, wherein the current collector has a measuring unit (36, 43, 53, 58) having a measuring device (38, 44, 59), at least two sensors (47, 48) of a sensor apparatus (46) of the measuring device being disposed on the positioning device or the sliding piece, measured values being registered in the sliding contact position in each case by means of the sensors, the measured values being processed by means of a processing apparatus (37, 49) of the measuring device, the method comprising, via the processing apparatus, putting the measured values into correlation with each other and determining a characteristic value describing an operating state of the current collector or the overhead contact line.