1.1 当使用的标准为集总阻抗时，这些试验方法包括测定固体电气绝缘材料试样的相对介电常数、损耗因数、损耗指数、功率因数、相位角和损耗角。所述频率范围从小于1赫兹扩展到几百兆赫。 注1: 在常见用法中，relative一词经常被省略。 1.2 这些测试方法提供了各种电极、仪器和测量技术的一般信息。对特定材料相关问题感兴趣的读者需要参考ASTM标准或直接适用于待测试材料的其他文件。 2. , 3. 1.3 本标准并不旨在解决与其使用相关的所有安全问题（如有）。 本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 有关具体危险说明，请参见 10.2.1 . 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 5.1 电容率- 绝缘材料通常以两种不同的方式使用( 1. )使电网各部件相互之间以及与地面之间相互支撑并绝缘，以及( 2. )充当电容器的电介质。对于首次使用，通常希望支架的电容尽可能小，符合可接受的机械、化学和耐热性能。因此，需要低介电常数。对于第二种用途，最好具有较高的介电常数值，以便电容器能够在物理上尽可能小。介电常数的中间值有时用于对导体边缘或端部的应力进行分级，以最小化交流电晕。中讨论了影响介电常数的因素 附录X3 . 5.2 交流损耗- 对于这两种情况（如电气绝缘和电容器介电），交流损耗通常需要较小，以减少材料的发热，并将其对网络其余部分的影响降至最低。 在高频应用中，损耗指数的低值特别可取，因为对于给定的损耗指数值，介电损耗随频率直接增加。在某些电介质配置中，例如用于端接套管和测试电缆的配置，有时会引入增加的损耗（通常是通过增加电导率获得的）来控制电压梯度。在比较具有近似相同介电常数的材料时，或在使用任何材料时，如果材料的介电常数基本保持不变，则还应考虑耗散系数、功率因数、相位角或损耗角。影响交流损耗的因素在 附录X3 . 5.3 相关性- 当有足够的相关数据可用时，耗散系数或功率因数可用于指示材料在其他方面的特性，如介电击穿、含水量、固化程度和任何原因引起的劣化。然而，除非材料随后暴露于湿气中，否则热老化引起的劣化可能不会影响耗散系数。虽然耗散因子的初始值很重要，但耗散因子随老化的变化往往更为显著。 5.4 电容是一个量的比值， q 电势差， 五、 。电容值始终为正。 当电荷以库仑表示，电势以伏特表示时，单位为法拉: 5.5 耗散系数(( D )，（损耗角正切），（tanδ））是损耗指数（κ“）与相对介电常数（κ′）的比值，其等于损耗角（δ）的正切或相位角（θ）的余切（参见 图1 和 图2 ). 耗散因子的倒数是质量因子， Q 有时称为存储因子。耗散系数， D 电容器的串联和并联表示形式相同，如下所示: 串联元件和并联元件之间的关系如下: 5.5.2 系列表示法- 而具有介电损耗的绝缘材料的平行表示( 图3 )通常是正确的表示，用电容表示单个频率的电容器总是可能的，有时也是可取的， C s ，与电阻串联， R s ( 图4 和 图2 ). 图3 并联电路 图4 串联电路 5.6 损耗角（（相位缺陷角），（δ））是正切为损耗因子或反正切的角 κ"/κ′ 或者它的余切是相位角。 5.6.1 相位角和损耗角的关系如所示 图1 和 图2 损耗角有时称为相位缺陷角。 5.7 损失指数（κ”（ε r “）是相对复介电常数虚部的大小；它是相对介电常数和损耗因子的乘积。 5.7.1 损失指数表示为: . 当功率损耗以瓦特为单位时，施加的电压以伏特每厘米为单位，频率以赫兹为单位，体积是施加电压的立方厘米，常数的值为5.556 × 10 −13 . 注2: 损失指数是国际商定的术语。在美国，κ”以前被称为损失因子。 5.8 相位角（θ）是余切为耗散因子arccotκ“/κ′的角度，也是施加在电介质上的正弦交流电压与产生的与电压频率相同的电流分量之间的相位角差。 5.8.1 相位角和损耗角的关系如所示 图1 和 图2 损耗角有时称为相位缺陷角。 5.9 功率因数( 功率因数 )是以瓦特为单位的功率比， W ，在材料中消散为有效正弦电压的乘积， 五、 、和当前， 我 ，单位为伏安。 5.9.1 功率因数表示为相位角θ的余弦（或损耗角δ的正弦）。 当耗散因数小于0.1时，功率因数与耗散因数的差值小于0.5 %. 它们之间的确切关系如下: 5.10 相对介电常数（相对介电常量）（SIC）κ′（ε r ))是相对复介电常数的实部。它也是等效并联电容的比值， C p 电极的给定配置，其材料为电容的电介质， C υ ，具有与电介质相同的真空（或最实用的空气）电极配置: 注3: 在常见用法中，“相对”一词经常被省略。 注4: 在实验上，真空必须在电容发生显著变化的所有点上被材料所取代。假设电介质的等效电路包括 C p 电容与电导平行。（请参见 图3 .) 注5: C x个 被认为是 C p ，等效并联电容如所示 图3 . 注6: 串联电容大于并联电容小于1 % 耗散系数为0。 1，且小于0.1 % 对于0.03的耗散系数。如果测量电路产生串联元件的结果，则并联电容必须根据 等式5 在计算修正值和介电常数之前。 注7: 干空气在23时的介电常数 °C，101.3 kPa时的标准压力为1.000536( 1. ). 6. 它与统一的分歧，κ′ − 1，与绝对温度成反比，与大气压力成正比。当空间在23℃被水蒸气饱和时，介电常数的增加 °C为0.00025( 2. , 3. )，并随温度（以摄氏度表示）近似线性变化，从10 °C至27 摄氏度。对于部分饱和，增加与相对湿度成正比。

1.1 These test methods cover the determination of relative permittivity, dissipation factor, loss index, power factor, phase angle, and loss angle of specimens of solid electrical insulating materials when the standards used are lumped impedances. The frequency range addressed extends from less than 1 Hz to several hundred megahertz. Note 1: In common usage, the word relative is frequently dropped. 1.2 These test methods provide general information on a variety of electrodes, apparatus, and measurement techniques. A reader interested in issues associated with a specific material needs to consult ASTM standards or other documents directly applicable to the material to be tested. 2 , 3 1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see 10.2.1 . 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. ====== Significance And Use ====== 5.1 Permittivity— Insulating materials are used in general in two distinct ways, ( 1 ) to support and insulate components of an electrical network from each other and from ground, and ( 2 ) to function as the dielectric of a capacitor. For the first use, it is generally desirable to have the capacitance of the support as small as possible, consistent with acceptable mechanical, chemical, and heat-resisting properties. A low value of permittivity is thus desirable. For the second use, it is desirable to have a high value of permittivity, so that the capacitor is able to be physically as small as possible. Intermediate values of permittivity are sometimes used for grading stresses at the edge or end of a conductor to minimize ac corona. Factors affecting permittivity are discussed in Appendix X3 . 5.2 AC Loss— For both cases (as electrical insulation and as capacitor dielectric) the ac loss generally needs to be small, both in order to reduce the heating of the material and to minimize its effect on the rest of the network. In high frequency applications, a low value of loss index is particularly desirable, since for a given value of loss index, the dielectric loss increases directly with frequency. In certain dielectric configurations such as are used in terminating bushings and cables for test, an increased loss, usually obtained from increased conductivity, is sometimes introduced to control the voltage gradient. In comparisons of materials having approximately the same permittivity or in the use of any material under such conditions that its permittivity remains essentially constant, it is potentially useful to consider also dissipation factor, power factor, phase angle, or loss angle. Factors affecting ac loss are discussed in Appendix X3 . 5.3 Correlation— When adequate correlating data are available, dissipation factor or power factor are useful to indicate the characteristics of a material in other respects such as dielectric breakdown, moisture content, degree of cure, and deterioration from any cause. However, it is possible that deterioration due to thermal aging will not affect dissipation factor unless the material is subsequently exposed to moisture. While the initial value of dissipation factor is important, the change in dissipation factor with aging is often much more significant. 5.4 Capacitance is the ratio of a quantity, q , of electricity to a potential difference, V . A capacitance value is always positive. The units are farads when the charge is expressed in coulombs and the potential in volts: 5.5 Dissipation factor (( D ), (loss tangent), (tan δ)) is the ratio of the loss index (κ") to the relative permittivity (κ′) which is equal to the tangent of its loss angle (δ) or the cotangent of its phase angle (θ) (see Fig. 1 and Fig. 2 ). The reciprocal of the dissipation factor is the quality factor, Q , sometimes called the storage factor. The dissipation factor, D , of the capacitor is the same for both the series and parallel representations as follows: The relationships between series and parallel components are as follows: 5.5.2 Series Representation— While the parallel representation of an insulating material having a dielectric loss ( Fig. 3 ) is usually the proper representation, it is always possible and occasionally desirable to represent a capacitor at a single frequency by a capacitance, C s , in series with a resistance, R s ( Fig. 4 and Fig. 2 ). FIG. 3 Parallel Circuit FIG. 4 Series Circuit 5.6 Loss angle ((phase defect angle), (δ)) is the angle whose tangent is the dissipation factor or arctan κ"/κ′ or whose cotangent is the phase angle. 5.6.1 The relation of phase angle and loss angle is shown in Fig. 1 and Fig. 2 . Loss angle is sometimes called the phase defect angle. 5.7 Loss index (κ" (ε r ") is the magnitude of the imaginary part of the relative complex permittivity; it is the product of the relative permittivity and dissipation factor. 5.7.1 The loss index is expressed as: . When the power loss is in watts, the applied voltage is in volts per centimeter, the frequency is in hertz, the volume is the cubic centimeters to which the voltage is applied, the constant has the value of 5.556 × 10 −13 . Note 2: Loss index is the term agreed upon internationally. In the United States, κ" was formerly called the loss factor. 5.8 Phase angle (θ) is the angle whose cotangent is the dissipation factor, arccot κ"/κ′ and is also the angular difference in the phase between the sinusoidal alternating voltage applied to a dielectric and the component of the resulting current having the same frequency as the voltage. 5.8.1 The relation of phase angle and loss angle is shown in Fig. 1 and Fig. 2 . Loss angle is sometimes called the phase defect angle. 5.9 Power factor ( PF ) is the ratio of the power in watts, W , dissipated in a material to the product of the effective sinusoidal voltage, V , and current, I , in volt-amperes. 5.9.1 Power factor is expressed as the cosine of the phase angle θ (or the sine of the loss angle δ). When the dissipation factor is less than 0.1, the power factor differs from the dissipation factor by less than 0.5 %. Their exact relationship is found from the following: 5.10 Relative permittivity ((relative dielectric constant) (SIC) κ′(ε r )) is the real part of the relative complex permittivity. It is also the ratio of the equivalent parallel capacitance, C p , of a given configuration of electrodes with a material as a dielectric to the capacitance, C υ , of the same configuration of electrodes with vacuum (or air for most practical purposes) as the dielectric: Note 3: In common usage the word “relative” is frequently dropped. Note 4: Experimentally, vacuum must be replaced by the material at all points where it makes a significant change in capacitance. The equivalent circuit of the dielectric is assumed to consist of C p , a capacitance in parallel with conductance. (See Fig. 3 .) Note 5: C x is taken to be C p , the equivalent parallel capacitance as shown in Fig. 3 . Note 6: The series capacitance is larger than the parallel capacitance by less than 1 % for a dissipation factor of 0.1, and by less than 0.1 % for a dissipation factor of 0.03. If a measuring circuit yields results in terms of series components, the parallel capacitance must be calculated from Eq 5 before the corrections and permittivity are calculated. Note 7: The permittivity of dry air at 23 °C and standard pressure at 101.3 kPa is 1.000536 ( 1 ). 6 Its divergence from unity, κ′ − 1, is inversely proportional to absolute temperature and directly proportional to atmospheric pressure. The increase in permittivity when the space is saturated with water vapor at 23 °C is 0.00025 ( 2 , 3 ), and varies approximately linearly with temperature expressed in degrees Celsius, from 10 °C to 27 °C. For partial saturation the increase is proportional to the relative humidity.