BS EN ISO 8654:2018 pdf free
BS EN ISO 8654:2018 pdf free.Jewellery – Colours of gold alloys – Definition, range of colours and designation (ISO 8654:2018)
This document specifies a limited number of colours of gold alloy and the method to measure colours.
It applies to objects made of gold alloys or coated by gold alloys.
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
For the purposes of this document, the following terms and definitions apply.
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three-dimensional space represented by the chromaticity coordinates x and y and Y
Note 1 to entry: As defined in CIE Publication No. 15, the values of Y correspond to the percentage values of the luminous reflectance factor.
The samples to be measured shall have a flat and polished surface to be used as a measurement area.
The measurement area shall be exempt of defect.
The finishing (polishing and washing) shall be (re)done until a mirror surface is achieved (Y reaches a constant value).
After polishing, the sample colour measurement shall be made within 120 min maximum.
NOTE Polishing, washing and environment conditions can greatly affect the colour.
Metallographic preparation is made with a final polishing with broadcloth charged with an abrasive solution. The solution contains 1 μm sized abrasive particles.
The recommended sample cleaning is done by gently wiping the surface with a clean soft cloth (microfibre) and some isopropylalcohol (IPA).
The measurement apparatus for the colour measurement of a gold alloy shall be in accordance to CIE Publication No.15.
The reference apparatus for the colour measurement of a gold alloy is an integrating sphere spectrophotometer able to measure spectral reflectance, with a measurement geometry compatible with designation di:8° or 8°:di (specular component included).
NOTE Other measurement geometries can be used as long as they do not affect significantly the colour results compared to the described measurement geometry.BS EN ISO 8654 pdf download.
