| CPC G07D 7/1205 (2017.05) [B42D 25/29 (2014.10)] | 12 Claims | 

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               1. A method for classifying a banknote having at least one luminescent feature, in which the following steps are carried out: 
            a) exciting the luminescent feature; 
                b) recording intensity values of the excited luminescent feature at a first time, at a second time that is different from the first time, and at least one further time between the first and second time; 
                c) determining a decay time of the luminescent feature by approximate integration over the recorded intensity values between the first time and the second time; 
                d) comparing the determined decay time with a reference decay time of the luminescent feature; and 
                e) classifying the banknote based on the comparison. 
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