Giesecke & Devrient Gmbh

Christoph Gerz

Klaus Thierauf

Methods and apparatuses for testing the authenticity of objects printed with security link are provided which measure light emanating from, in particular reflected or transmitted by, an object to be checked. To guarantee especially reliable authenticity testing, it is provided that light emanating from the object to be checked is detected indifferent spectral regions outside the visible spectral region. To obtain easily operated and safe authenticity testing, it is provided that light emanating from the object is detected at a plurality of places on the object in at least two selected spectral regions. A test series is produced for each spectral region wherein two test series adapted to each other, and authenticity testing is then performed by comparing the adapted two test series.

Methods and devices for testing the color fastness of imprinted objects

Method for detecting an electroconductive element in a document

The invention relates to a method and apparatus for dynamic determination of the thickness and/or basis weight of moving material under test. The material under test is exposed to a focused ultrasound filed with high sound intensity, whereby the sound fraction coming from the material under test is detected directly in the near filed, i.e. at a distance smaller than or equal to the acoustic wavelength used, and evaluated for determining the thickness and/or basis weight. The near-field measurement preferably takes place with continuous sound and in transmission.

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Germering, Germany

Christoph Gerz