The stability of the ColourQ 2100 measurements is well illustrated by an instrument in a refinery, where it controls the spray water for uniform sugar colour. The instrument was calibrated in 2002. In 2012 the good results of the instrument were presented by the refinery at the SIT conference in Auckland, New Zealand (see the article in International Sugar Journal 2012, vol. 114, No. 1367, pp. 804-809). In 2016 the instrument is still running with the calibration made in 2002.
In general, the ColourQ 2100 needs calibration at commissioning only. Unless the instrument is moved or the conveyor modified, the calibration rarely needs update. Less than 5% of all installed instruments have been recalibrated after commissioning.