Abstract: The invention concerns a device and a method for examining magnetic properties of objects, in particular of sheet material such as for example bank notes. Therein the invention proceeds from a device and a method for examining magnetic properties of objects with a magneto-optical layer having magnetic domains, the optical properties of the magneto-optical layer being influenced by the magnetic properties of the object to be examined, at least one light source for the generation of light incident upon the magneto-optical layer, and at least one sensor for the reception of light which is transmitted and/or reflected by the magneto-optical layer, with a magnetic filed in the area of the magneto-optical layer which extends substantially parallel to the surface of the magneto-optical layer.

Abstract: A rotation and/or tilt angle detection device for a ball and socket joint is provided wherein at least one magnet (2), especially a permanent magnet, is arranged in the joint ball (1a), wherein a display device (4) displays the magnetic field of the at least one magnet (2) by means of the magnetooptic effect. An image detection deice (10) detects the information displayed by the display device (4). A data processing unit (50) calculates the relative position of the joint ball (1a) and the ball socket (3) of the ball and socket joint on the basis of the information detected.