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Digital colorimeter measuring a sample. The colorimeter measures the absorbance of different wavelengths of light by a liquid sample. The absorbance is directly proportional to the concentration of the absorbing substance, according to the Beer-Lambert Law. Here a dilute sample of beetroot juice is being studied. Absorbance is measured on a logarithmic scale from 0 to infinity, although 0 to 2 is the most useful range.
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