1.1 These test methods outline procedures for testing samples of vitrified ceramic materials that are to be used as electrical insulation. Where specified limits are mentioned herein, they shall not be interpreted as specification limits for completed insulators.

1.2 These test methods are intended to apply to unglazed specimens, but they may be equally suited for testing glazed specimens. The report section shall indicate whether glazed or unglazed specimens were tested.

1.3 The test methods appear as follows:

Procedure Section Compressive strength 6 C 773 Dielectric strength 13 D 618, D 149 Elastic properties 8 C 623 Electrical resistivity 15 D 618, D 257, D 1829 Flexural strength 7 C 674, F 417 Hardness 9 C 730, E 18 Porosity 5 C 373 Relative permittivity and dissipation factor 14 D 150, D 2149, D 2520 Specific gravity 4 C 20, C 329, F 77 Thermal conductivity 10 C 177, C 408 Thermal expansion 12 C 539, E 228 Thermal shock resistance 11

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precaution statements are given in 11.3, 13.5, and 15.3.