Patent ID: 7763469

Claim:
Method for automatic marking of liquids using encryption, the method including following steps: selecting at least two, preferably more markers, which are miscible in a liquid to be marked and which have characteristic spectral features for distinguishing them from the marked liquid without the need to extract said markers from the marked liquid, while characteristic features are marker's optical absorption spectra or fluorescence (excitation/emission) spectra must be clearly distinguished within at least one wavelength range, within which the absorption spectra or the fluorescence spectra (or both) of different markers are mutually different, and in addition to that they must differ from both the absorption spectrum or the fluorescence spectrum of the marked liquid itself and also from the absorption spectrum or the fluorescence spectrum of any other marker also used in this liquid, determining quantities of markers to be introduced into the marked liquid, introducing markers to the liquid to be marked, and determining concentration of each single marker and calculating mutual relationships between markers concentrations in marked liquid, and forming, on the bases of these data, for each marked liquid an unique identifying marking code characteristic only to this liquid volume, whereby the method is characterized by the following steps: generating for each marker to be introduced into a liquid to be marked of a random number, the value of which determines the number of fixed volume portions of the marker to be introduced into the liquid to be marked, introducing markers into a liquid to be marked automatically without human involvement checking and if necessary adjusting the marking code immediately after the marking is completed, and encrypting the marking code identifying the marked liquid.