Patent ID: 8076643

Claim:
Detection apparatus for determining the presence, absence or characteristic of a security ink on a sample, the apparatus comprising: (a) a radiation source for providing excitation radiation of a first measurable frequency spectrum to the sample; (b) a detector for detecting radiation of a second measurable frequency spectrum emitted from the sample subsequently and as a result of providing said excitation radiation to said sample; and (c) a processor arranged in use to determine the presence, absence or characteristic of said ink on the sample according to analysis of the detected spectrum of radiation subsequently emitted from the sample in response to providing said excitation spectrum to said sample by measuring the frequency of radiation emitted from the sample in the same part of the spectrum as the frequency of excitation subsequently following said excitation; and by subsequently automatically adjusting the intensity of a subsequent excitation radiation of said first frequency spectrum from said radiation source thereafter depending on the detected strength of detected radiation frequency spectrum emitted from the sample.