The VSC 5000 enables four types of spectra between 400 and 1000nm to be measured - absorption, reflectance, transmittance and fluorescence. These may be used as further aids in the identification of counterfeit documents.

Absorption and reflectance spectra are measured with reference to a standard white tile to provide absolute measurement. Transmission spectra are measured with a dual beam system for normalisation. Fluorescence spectra are measured without a reference signal, and are therefore subject to the spectral characteristics of the camera and lighting. Weak fluorescence may be integrated by up to 30 minutes before analysis, considerably enhancing the sensitivity of the spectrometer in this application.

The VSC 5000 also provides a number of facilities for processing spectra; normalisation, to eliminate the effects of a background to allow spectra on different substrates to be compared; subtraction, to highlight differences in spectra and differentiation to identify wavelengths of greatest change.

Spectra may be retained in document records under the VSC 5000's general casework management system.

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