3.1 For any given ceramic composition, one or more of the properties covered herein may be of more importance for a given insulating application than the other properties. Thus, it may be appropriate that selected properties be specified for testing these ceramic materials.

3.2 Pertinent statements of the significance of individual properties may be found in the sections pertaining to such properties.

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

C773

Dielectric strength

13

D618, D149

Elastic properties

 8

C623

Electrical resistivity

15

D618, D257, D1829

Flexural strength

 7

C674, F417

Hardness

 9

C730, E18

Porosity

 5

C373

Relative permittivity and dissipation factor

14

D150, D2149, D2520

Specific gravity

 4

C20, C329, F77

Thermal conductivity

10

C177, C408

Thermal expansion

12

C539, E288

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.