What is ISO 4630 - Clear 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 is ISO 4630 - Clear liquid gardner scale standard for?
ISO 4630 on clear liquid gardner scale standard is useful for:
- Manufacturers of paints and varnishes
- Concerned maintenance teams
- Product development / innovation / research teams
- Quality control teams
Why should you use ISO 4630 - Clear liquid gardner scale standard?
The yellowness of the transparent liquid is determined by pouring the sample into a tube and comparing it to a pre-determined and known standard. The standard that the sample falls closest to then becomes the value for the liquid. ISO 4630 is applicable to drying oils, varnishes, and solutions of fatty acids, polymerized fatty acids, resins, tall oil, tall oil fatty acids, rosin, and related products.
The results might be invalid if other products are tested. The method described provides a more precise way of measuring Gardner colour than a visual sample comparison using human eyes. It is applicable to products having colours from Gardner 1 to Gardner 18. The Gardner scale is not applicable to products with colours darker than 18. ISO 4630 gives you thorough details on apparatus and materials, sampling and procedure apart from expression of results and precision. Using ISO 4630 guidelines, you can estimate the colour of optically clear, yellow/brownish coloured liquid products by means of the Gardner colour scale using colour-measuring instruments. ISO 4630 guidelines enable you to provide your customers with suitable, reliable, and high-quality products.
What’s changed since the last update?
BS EN ISO 4630:2015 supersedes BS EN ISO 4630-1:2004 and BS EN ISO 4630-2:2004. BS EN ISO 4630:2015 includes some technical changes with respect BS EN ISO 4630-1:2004 and BS EN ISO 4630-2:2004. These include:
- Both standards have been combined into one standard
- The spectrophotometric method (formerly described in ISO 4630-2:2004) is the only one standardized now
- the original visual comparison of colours (formerly described in ISO 4630-1:2004) has been deleted, and the description of manufacture of the original Gardner colour standards has been moved to Annex A.