Patent ID: 7437897

Claim:
Dyeing machine comprising: a container ( 11 ) in which products to be dyed are placed; a source ( 12 ) of coloring liquids adding liquids on command into the container to realize a dye dip; a unit ( 13 ) to circulate the dye dip with respect to the product; spectroscopic analysis means to perform a spectroscopic analysis on the liquids and an electronic control and calculation device ( 15 ) receiving the spectroscopic analysis data and calculating therefrom the concentrations of the various dyes in the dip on the basis of previously memorized spectroscopic information for the individual dyes; characterized in that the spectroscopic analysis means comprise a sampling and analysis device ( 14 ), which during the dyeing process automatically takes liquid samples in the container to a reading cell ( 18 ), at intervals, and performs a spectroscopic analysis on the taken samples in the reading cell ( 18 ); and characterized in that the sampling and analysis device ( 14 ) comprises a reading cell ( 18 ) having a passage ( 26 ) for the liquid with controlled variable gauge (d) and through said gauge (d) is made to pass a measuring light detected, after the passage, by a spectrophotometer ( 20 ) sending the data to said electronic device ( 15 ) which performs the spectroscopic analysis for calculation of the concentrations.