This standard is included in DIN HDBK 486. Defines two low voltage tests to detect and locate defects that extend to the basis metal in porcelain and vitreous porcelain enamel coatings. Method A (electrical) is suitable for rapid detection and determination of general location of defects. Method B (optical), based on colour effects, is suited to the more precise detection of defects and their exact locations. Method A is commonly applied to flat surfaces where method B is for more intricate shapes.