BS EN ISO 4630:2015

What is ISO 4630 - C lear liquid gardner scale standard about?   

Colours of transparent liquids have been studied visually since the early 19th century. Changes in colour can indicate contamination or impurities in the raw materials, process variations, or degradation of products over time. The Gardner Colour Scale is a one-dimensional scale used to measure the shade of the colour yellow. The Gardner scale and the APHA/Pt-Co/Hazen Colour Scale overlap with the Gardner scale measuring higher concentrations of yellow colour and the APHA scale measuring very low levels of yellow colour.  
ISO 4630 specifies a method for estimating the colour of optically clear, yellow/brownish coloured liquid products by means of the Gardner colour scale using colour-measuring instruments.  
Note: The method uses the Gardner colour scale described in Annex A. 

Who...