Mobile reading device, and method for locating an object that is marked with an active transponder

The invention relates to a mobile reading device for locating an object that is marked with a transponder. The reading device has an antenna device (110) for receiving a signal transmitted by the transponder, said antenna device having a main radiation direction. Furthermore, an electronic assembly is provided for calculating a direction from the reading device to the transponder using the received signal. The reading device further has an orientation detector, an electronic compass for example, with which an absolute orientation of the reading device with respect to an exterior region can be detected. While the main radiation direction of the antenna is pivoted in the region and the signal strength is measured, the orientation in the region is simultaneously detected. A correlation of the orientation that is detected at a point in time t to the signal strength that is measured at the same point in time allows the determination of the direction to the transponder because it can be assumed that the signal has