Colour measurement for process control in-line measurement of sugar colour in IU420 units

Using ICUMSA Method 4, sugar colour is measured in the laboratory with a spectrophotometer. The time needed for sample preparation and measurement is incompatible with the requirements of process control. The instrument described here (the Neltec ColourQ 800) can take measurements in the process and the result is delivered within seconds, with a good correlation to the laboratory measurements. More than 30 systems have been installed in sugar factories, for process or quality control. Some aspects of the operation are discussed, together with installation, initial calibration, precision, and tests of the system.