ISO 10216:2017

INTERNATIONAL ISO
STANDARD 10216
Third edition
2017-10
Anodizing of aluminium and its
alloys — Instrumental determination
of image clarity of anodic oxidation
coatings — Instrumental method
Anodisation de l'aluminium et de ses alliages — Détermination de la
netteté d'image sur couches anodiques — Méthode instrumentale
Reference number
©
ISO 2017
© ISO 2017, Published in Switzerland
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ii © ISO 2017 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
6 Test specimen . 4
6.1 Sampling . 4
6.2 Size . 4
6.3 Treatment before measurement . 5
7 Procedure. 5
7.1 Measurement of black glass . 5
7.2 Sensitivity adjustment by test specimen . 5
7.3 Measurement of test specimen . 5
8 Expression of results . 5
8.1 Calculation of image clarity, C . 5
n
8.2 Image clarity . 7
8.3 Image clarity comparison and classification . 7
8.4 Optical evenness, E .7
8.5 Dispersion of light, D .7
9 Test report . 8
Bibliography . 9
Foreword
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URL: www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 79, Light metals and their alloys,
Subcommittee SC 2, Organic and anodic oxidation coatings on aluminium.
This third edition cancels and replaces the second edition (ISO 10216:2010), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— the tolerance of the width of the slit has been revised;
— the figures have been revised;
— a combed sliding shutter figure has been added;
— information about the test specimen has been added.
iv © ISO 2017 – All rights reserved

Introduction
Estimation of the image clarity of anodic oxidation coatings on aluminium and its alloys is normally
carried out visually by observing the clearness of an image on the surface. However, the image can be
observed at various angles and be confused with the gloss level of a surface, and while the degree of
image clarity is mainly influenced by the clearness of the coating, it is also affected by image distortion
caused by surface irregularities and the haziness of the coating layer. Standardized methods of
determining image clarity are therefore required.
This document specifies the use of an instrumental method for measuring image clarity using an optical
comb. A related document, ISO 10215, specifies the use of a chart scale also based on an optical comb
together with a lightness scale to rank image clarity.
NOTE This instrumental method provides more accurate measurements of image clarity than visual
evaluation and can be used in cases of dispute.
INTERNATIONAL STANDARD ISO 10216:2017(E)
Anodizing of aluminium and its alloys — Instrumental
determination of image clarity of anodic oxidation coatings
— Instrumental method
1 Scope
This document specifies an instrumental method for determining the image clarity of anodic oxidation
coatings on aluminium and its alloys by measuring reflection from the surface with the help of a sliding
combed shutter.
The test can only be applied to a flat surface which can reflect the image onto the limited combed
shutter and photo-receiver. This method can also be used to measure the optical evenness of anodic
oxidation coatings on aluminium and its alloys.
2 Normative references
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 a
...