| 摘要 |
The invention relates to devices and corresponding method for investigating the magnetic properties of objects, in particular sheet material, such as for example banknotes (20). The devices comprise a magneto-optical layer (10), the optical properties of which may be influenced by the magnetic properties of the object under test, a light source (11), for the generation of light, which may be coupled with the magneto-optical layer (10) and a detector (13) for the detection of light transmitted and/or reflected from the magneto-optical layer (10). Reliable investigation of the magnetic properties of sheet material can be achieved, whereby the dispersion direction of the coupled light runs parallel to a base surface (9) on the magneto-optical layer (10). By means of the above invention, the magnetic properties of objects, in particular magnetic regions of sheet material from which only a very weak magnetic field emanates can be investigated with high sensitivity and reliability. |
