ISO 2746 is an International Standard that describes two test methods of high voltage testing:
The tests are performed using DC or pulsed DC high voltage and are applicable to dry surfaces of enamel coatings. In the case of moist surfaces, care should be taken to ensure that the locating of any defects is correctly performed.
Since test voltages depend on the coating thickness, the test method, especially with test A, may not be suitable for test specimens for which the coating thickness varies to a large extent.
ISO 2746 on vitreous and porcelain enamel testing is useful for:
Vitreous enamel, or porcelain enamel, is created by burning powdered glass onto a substrate. ISO 2746 provides you with two different objectives for high voltage testing of vitreous and porcelain enamels.
ISO 2746 provides test A that can help you in detection and locating defects, which extend down to the metal base. This is a non-destructive test usually applied to thin enamel coatings. The test serves to monitor either that the parts produced are free from defects at the chosen test voltage, or to count the number of existing defects, e.g. to determine the defect density of enamelled architecture panels.
ISO 2746 elaborates on Test B, that can help you in detection and locating defects, which extend down to the metal base and to detect weak spots. This is a destructive test, i.e. the test can generate open pores with an electric discharge through weak spots in the enamel coating. This test is usually applied to thick enamel coatings.
The tests provided in ISO 2746 help you to verify whether an enamel coating is safe to be used under highly corrosive conditions. ISO 2746 also assists you in verifying whether the enamel coating is safe to be used as a dielectric.
EN ISO 2746:2015
ISO 2746:2015