ASTM D2413-16(2022)

5.1?Dissipation Factor and Relative PermittivityKnowledge of these properties is important in the design of electrical equipment such as cables, transformers, insulators, and so forth. The numerical product of these two properties of a dielectric system is proportional to the energy loss converted to heat, and is called its loss index (see Terminology D1711). The energy loss reduces the efficiency of electrical equipment. The heat produced tends to chemically degrade the dielectric material and may even lead to thermal runaway. Test results of impregnated specimens can disclose significant differences between combinations of papers and oils that appear similar when the papers and the oils are tested separately. Dissipation factor, particularly at elevated temperatures, is often changed significantly by the presence of a small quantity of impurities in either the liquid or the paper. This practice is useful in the comparison of materials and in evaluating the effects of different papers on a given liquid. Judicious analysis of results with respect to time, temperature, and field strength are useful in predicting the performance and capabilities of systems using the paper and the liquid. For additional information on the significance of dissipation factor and relative permittivity, see Test Methods D150.

5.2?Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies:?

5.3?Dielectric Breakdown Voltage and Dielectric Strength Under Impulse ConditionsTesting impregnated paper or board under impulse conditions can yield useful data for the designer of electrical equipment. The test results are useful in the comparison of materials and for research studies. For a more general treatise on the significance of impulse testing see Test Method D3426.

1.1?This practice covers the preparation of insulating paper and board impregnated with a liquid dielectric. Where this practice states only paper, the same procedure shall apply to board.

1.2?This practice has been found practicable for papers having nominal thickness of 0.05 mm (2 mil) and above. It has been used successfully for insulating board as thick as 6 mm (¹/₄?in.) when care is taken to ensure the specimen geometry necessary for valid measurement of dielectric properties. Suitable geometry depends on the electrode system used. Rigid solid opposing electrodes require flat specimens that have essentially parallel surfaces.

1.3?The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.