ISO 3210:2010 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. ISO 3210:2010 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 severe applications, Method 1 may be more suitable. The methods are not applicable to the following: 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.