In order to be able to operate a sensor device on a feed pipeline carrying high voltage without using batteries or storage batteries, the sensors are connected for supply purposes via an electrical isolating stage to a mains voltage source and for signal purposes to an evaluation circuit. The display unit can be oriented in landscape and portrait orientations, or can be replaced by display units having different physical characteristics. Next, one makes available a placement and orientation insert that has an annular peripheral fixing structure designed to cooperate with the receiving face of the external annular receiving structure by engaging around the external annular receiving structure. The Si varies depending on the assigned Wi and when the user entered the scheduling session. The piston rod is connected to the piston head. The spacecraft has a number of reaction wheels and a number of antennas.