This standard specifies the general method for the measurement of colour with visual colorimetry in adoption of platinum-cobalt standard solution as the standard colour.
This standard is applicable to the measurement of colour of clear, transparent and light liquid reagent whose colour melody is close to platinum-cobalt standard solution. Where this standard is adopted for the measurement of colour, the testing lower limit is 4 Hazen units.
This standard is not applicable to the measurement of readily carbonizable substances.
