Clear liquids - Estimation of colour by the platinum-cobalt scale - Part K13: Spectrophotometric method (ISO 6271-2:2004, IDT)
This part of ISO 6271 specifies a spectrophotometric method for estimating the colour, in Pt-Co units, of clear
liquids. It is applicable to clear liquids having a colour characteristic similar to those of the reference platinumcobalt scale specified in ISO 6271-1.
The method described provides a more precise way of measuring Pt-Co colour than that described in
ISO 6271-1.
NOTE The term “platinum-cobalt colour (Pt-Co colour)” used here is preferred over the terms “Hazen colour” and “APHA
colour”.
