Device for optically determining the concentration of alcohol and carbohydrates in a liquid sample

A device installed in a production line for optically determining a concentration of alcohol and carbohydrates in a liquid sample, comprising:

• a first and a second light source arranged for exposing and emitting light through the liquid sample having a wavelength ranging between 750 nm and 1000 nm from the first and second light source as the liquid sample is passing through a measuring chamber in the production line;
• a spectrometer arranged to determine a first and a second light intensity by measuring the light from the first and the second light source emitted through the liquid sample;
• a temperature sensor for measuring a temperature of said liquid sample in the production line;
• a processing unit connected to the spectrometer and arranged to determine an absorption value of the liquid sample from a comparison of the first and the second light intensity with a reference value and
• two polarization filters for filtering the light from the first light source, wherein:
• the processing unit is further arranged to calculate and present the concentration of alcohol from the proportion of the absorption at a wavelength of less than 900 nm and the wavelength range between 900 nm and 920 nm, and to calculate and present the concentration of carbohydrates from the proportion of the absorption in the wavelength range between 750 nm and 900 nm and at a wavelength of 900 nm, wherein the processing unit is arranged to determine if the measured temperature in the production line is outside of a predetermined range, and wherein an outcome thereof defines reliability of the calculated concentrations;
• and
• the first polarization filter is positioned between the first light source and the liquid sample and the second polarization is positioned between the liquid sample and the spectrometer, and wherein the liquid sample is selected from the group consisting of beer, wine, liquors, low-alcohol beer, non-alcoholic beer, and soft drinks.