Abstract: Apparatus for detection of infrared radiation emitted from a taggant following excitation of the taggant sample measures the decay time of the radiation used. If the decay characteristic is accurately measured, the particular taggant can be accurately identified. The apparatus comprises an electronic controller, light-emitting diodes, a photo-detector, a first amplifier, a three-way sampling switch, filter/stores, second amplifiers and an output display. The infrared emission is excited by repeatedly illuminating the taggant for a period of microseconds every few milliseconds. When the light source is turned off, the sample continues radiating for a few milliseconds. The emission is detected by photo-detector sensitive to the 800 to 1000 nm waveband thereby rejecting interference from visible light sources.

Abstract: A code system for associating data with articles having codes each code having a uniquely created, non-informational first part and a second part wherein each code is associated with an article and the first part may be transformed and thereby uniquely associated with an individual article and a second part may be associated with the first part, such that a relationship between the parts, or lack thereof may be discerned by reading both parts of the code, in order to verify the authenticity of the code.

Abstract: Apparatus for detection of infrared radiation emitted from a taggant following excitation of the taggant sample measures the decay time of the radiation used. If the decay characteristic is accurately measured, the particular taggant can be accurately identified. The apparatus comprises an electronic controller, light-emitting diodes, a photo-detector, a first amplifier, a three-way sampling switch, filter/stores, second amplifiers and an output display. The infrared emission is excited by repeatedly illuminating the taggant for a period of microseconds every few milliseconds. When the light source is turned off, the sample continues radiating for a few milliseconds. The emission is detected by photo-detector sensitive to the 800 to 1000 nm waveband thereby rejecting interference from visible light sources.