1.1 此测试方法 2 提供了用于评估刚性电绝缘材料的耐热性的程序。介电强度、弯曲强度或吸水率是在选定的高温下在空气中老化增加的时间后在室温下测定的。在每个老化温度下使用选定的终点绘制耐热性曲线图。描述了一种通过将耐热性图外推到选定时间来确定温度指数的方法。 1.2 该测试方法最适用于刚性电绝缘，如支架、垫片、电压屏障、线圈形式、端子板、电路板和外壳，用于许多类型的应用，其中热老化后所选性能的保持很重要。 1.3 当使用介电强度作为老化标准时，也可以对一些薄板（柔性）材料使用此测试方法，这些材料随着热老化而变得坚硬，但不打算取代测试方法 830美元 对于那些在使用中必须保持一定程度灵活性的材料。 1.4 本试验方法不适用于陶瓷、玻璃或类似无机材料。 1.5 以公制单位表示的数值应视为标准。其他单位（括号内）仅供参考。 1.6 在确定刚性EIM的耐热性时，本标准中的基本概念遵循IEEE 1、IEEE 98和IEEE 101。 1.7 本标准并非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。 中给出了具体的警告声明 11.3.4 。 1.8 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 6.1 热降解通常是影响绝缘材料及其使用设备寿命的主要因素。温度指数提供了一种方法，用于比较不同材料在选定性能退化方面的热性能（老化标准）。此属性需要直接或间接地表示应用程序中的功能需求。例如，介电强度的变化可能具有直接的功能重要性。然而，更常见的情况是，介电强度的降低可能会间接表明出现不希望的裂纹（脆化）。 弯曲强度的降低在某些应用中可能具有直接的重要性，但也有可能间接表明振动中的失效易感性。通常，有必要使用两个或多个失效标准；例如介电强度和弯曲强度。 6.2 其他因素，如振动、湿气和污染物，有可能在发生热降解后导致故障。在这种测试方法中，吸水性提供了一种评估这些考虑因素的方法。 6.3 对于某些应用，该测试方法中的老化标准将不是最合适的。 其他标准，如拉伸或弯曲失效时的伸长率，或暴露于高湿度或重量损失后的电阻率，有可能起到更好的作用。该试验方法中的程序有可能与此类老化标准一起使用。重要的是要考虑材料的性质及其应用。例如，拉伸强度可能是玻璃纤维增强层压板的不良选择，因为即使相关树脂严重劣化，玻璃纤维也可能保持拉伸强度。 在这种情况下，弯曲强度是热老化的更好标准。 6.4 当根据应用的需要而定时，可能需要并使用除空气以外的老化气氛。例如，热老化可以在无氧的氮气氛中进行。

1.1 This test method 2 provides procedures for evaluating the thermal endurance of rigid electrical insulating materials. Dielectric strength, flexural strength, or water absorption are determined at room temperature after aging for increasing periods of time in air at selected-elevated temperatures. A thermal-endurance graph is plotted using a selected end point at each aging temperature. A means is described for determining a temperature index by extrapolation of the thermal endurance graph to a selected time. 1.2 This test method is most applicable to rigid electrical insulation such as supports, spacers, voltage barriers, coil forms, terminal boards, circuit boards and enclosures for many types of application where retention of the selected property after heat aging is important. 1.3 When dielectric strength is used as the aging criterion, it is also acceptable to use this test method for some thin sheet (flexible) materials, which become rigid with thermal aging, but is not intended to replace Test Method D1830 for those materials which must retain a degree of flexibility in use. 1.4 This test method is not applicable to ceramics, glass, or similar inorganic materials. 1.5 The values stated in metric units are to be regarded as standard. Other units (in parentheses) are provided for information. 1.6 When determining the thermal endurance of rigid EIM, the basic concepts in this standard follow IEEE 1, IEEE 98, and IEEE 101. 1.7 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. A specific warning statement is given in 11.3.4 . 1.8 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 ====== 6.1 Thermal degradation is often a major factor affecting the life of insulating materials and the equipment in which they are used. The temperature index provides a means for comparing the thermal capability of different materials in respect to the degradation of a selected property (the aging criterion). This property needs to directly or indirectly represent functional needs in application. For example, it is possible that a change in dielectric strength will be of direct, functional importance. However, more often it is possible that a decrease in dielectric strength will indirectly indicate the development of undesirable cracking (embrittlement). A decrease in flexural strength has the potential to be of direct importance in some applications, but also has the potential to indirectly indicate a susceptibility to failure in vibration. Often, it is necessary that two or more criteria of failure be used; for example, dielectric strength and flexural strength. 6.2 Other factors, such as vibration, moisture and contaminants, have the potential to cause failure after thermal degradation takes place. In this test method, water absorption provides one means to evaluate such considerations. 6.3 For some applications, the aging criteria in this test method will not be the most suitable. Other criteria, such as elongation at tensile or flexural failure, or resistivity after exposure to high humidity or weight loss, have the potential to serve better. The procedures in this test method have the potential to be used with such aging criteria. It is important to consider both the nature of the material and its application. For example, it is possible that tensile strength will be a poor choice for glass-fiber reinforced laminates, because it is possible that the glass fiber will maintain the tensile strength even when the associated resin is badly deteriorated. In this case, flexural strength is a better criterion of thermal aging. 6.4 When dictated by the needs of the application, it is possible that an aging atmosphere other than air will be needed and used. For example, thermal aging can be conducted in an oxygen-free, nitrogen atmosphere.