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Applied Photophysics Limited

Michael Anthony West

Marking of articles

Apparatus and process for checking the authenticity of an article having

In characterizing or identifying an article which is provided with luminescent material, excitation radiation is directed at the article to cause emission from the luminescent material and the intensity of emitted radiation at different wavelengths is compared by directing the emitted radiation to photodetectors through a plurality of optical systems having respective filters of different wavelength transmission and comparing the modified signal level from one photodetector with the signal level from another photodetector.

Characterizing and identifying materials

A spectrofluorimeter for measuring excitation and emission spectra uses a flash or pulsed light source, an excitation monochrometer adjustable by a stepping motor, a first optical system for directing radiation onto a sample under test, a reference light detector for monitoring the excitation radiation, an emission monochrometer, also adjustable by a stepping motor, for receiving radiation via a second optical system from the sample and directing selected wavelengths to a detection photomultiplier, the first and second optical systems being corrected for spherical and chromatic alterations.

Growing community of inventors

London, United Kingdom

Michael Anthony West