DIN EN ISO 3210:2010-12

This document specifies methods of assessing the quality of sealed anodic oxidation coatings on aluminium and its alloys by measurement of the loss of mass after immersion in phosphoric acid/chromic acid solution. This document consists of the following two methods. Method 1: Assessment of quality of sealed anodic oxidation coatings by measurement of the loss of mass after immersion in phosphoric acid/chromic acid solution without prior acid treatment. Method 2: Assessment of quality of sealed anodic oxidation coatings by measurement of the loss of mass after immersion in phosphoric acid/chromic acid solution with prior acid treatment. Method 1 is applicable to anodic oxidation coatings intended for decorative or protective purposes or where resistance to staining is important. Method 2 is applicable to anodic oxidation coatings intended for architectural purposes. For less serve application, Method 1 may be more suitable. The methods are not applicable to: - hard-type anodic oxidation coatings which normally are not sealed; - anodic oxidation coatings that have been sealed only in dichromate solutions; - anodic oxidation coatings produced in chromic acid solutions; - anodic oxidation coatings that have undergone a treatment to render them hydrophobic. The methods are destructive and can serve as a reference methods in case of doubt or dispute regarding the results of the test for loss of absorptive power ISO 2143, or the measurement of admittance ISO 2931.