| 摘要 |
The invention relates to a method and an apparatus for checking documents of value which have a security element with several magnetic areas, including at least one high-coercive magnetic area, at least one low-coercive magnetic area and at least one combined magnetic area which contains both the high-coercive and the low-coercive magnetic material. After the magnetization of all magnetic areas in a first direction, first magnetic signals of the security element are detected with a first magnetic detector. After a subsequent second magnetizing, which is effected antiparallel to the first magnetizing and magnetically reverses only the low-coercive magnetic material, second magnetic signals of the security element are detected. For identifying the magnetic areas, the second magnetic signals or a signal derived therefrom are compared with two thresholds. |
