Patent ID: 8379202

Claim:
A method for detecting contaminants in an optical measuring cuvette of a spectrophotometer comprising: performing at least one sample measurement in a measuring cuvette to obtain a sample spectrum I(λ), performing at least one reference measurement in said measuring cuvette using a reference liquid to obtain a reference spectrum I 0 (λ), comparing the reference spectrum I 0 (λ)to a known target spectrum I 0soll (λ), which is associated with the measuring cuvette, to obtain comparison parameters, and deciding automatically as a function of predefined threshold values of the comparison parameters whether a contamination of the measuring cuvette exists, wherein a predefined pattern spectrum I p is selected, which has at least one typical absorption peak of one or more contaminants, the spectral curve of the incorrect absorption caused by the contaminants from the reference spectrum I 0 (λ)in relation to the target spectrum I 0soll (λ) is determined, the spectral curve of the incorrect absorption is compared to the selected pattern spectrum I p using folding, and the curve shape obtained from the folding is subjected to a weighted evaluation and comparison parameters are obtained therefrom.