Clear liquids - Estimation of colour by the platinum-cobalt scale - Part 1: Visual method
1 Scope
This part of GB/T 9282 specifies a method for estimating the colour, in Pt-Co units, of clear liquids.
It is applicable to clear liquids having colour characteristics similar to those of the reference platinum-cobalt scale.
2 Normative references
The following documents contain provisions which, through reference in this part of GB/T 9282, constitute provisions of this part. For dated references, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest edition of the normative document applies.
GB/T 3186 Paints, varnishes and raw materials for paints and varnishes - Sampling (GB/T 3186-2006, ISO 15528: 2000, IDT)
GB/T 6682 Water for analytical laboratory use Specification and test methods (GB/T 6682-1992, neq ISO 3696: 1987)
3 Terms and definitions
For the purposes of this part, the following terms and definitions apply.
3.1
Pt-Co scale
classification of the colour of a solution containing platinum, in the form of the hexachloroplatinate (IV) ion, and cobalt (II) chloride hexahydrate in specified concentrations
4 Principle
The colour of a sample of the product to be tested is compared with those of colour standards. The standard that most closely matches the colour of the sample is identified and the result is expressed in terms of Pt-Co units.
5 Reagents
During the test, use only reagents of recognized analytical grade and only water of at least grade 3 purity as defined in GB/T 6682.
5.1 Potassium hexachloroplatinate (IV), K2PtCl6.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Reagents
6 Apparatus
7 Preparation of colour standard
8 Sampling
9 Procedure
10 Expression of results
11 Test report
Annex A (Informative) Technical deviations between this part and ISO 6271-1:2004, together with their justifications
