ISO 2746:2015描述了两种高压测试方法: -测试A用于检测和定位釉瓷和搪瓷中的缺陷； -测试B用于检测和定位釉瓷和搪瓷中的缺陷和薄弱点。 使用直流或脉冲直流高压进行测试。 本试验适用于搪瓷涂层的干燥表面。对于潮湿表面，应注意确保正确定位任何缺陷。 由于试验电压取决于涂层厚度，试验方法，尤其是试验A，可能不适用于涂层厚度变化很大的试样。

ISO 2746:2015 describes two test methods of high voltage testing: - Test A is used to detect and locate defects in vitreous and porcelain enamels; - Test B is used to detect and locate defects and weak spots in vitreous and porcelain enamels. The tests are performed using DC or pulsed DC high voltage. The tests 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.