1.1 本试验方法包括通过测量简单加载玻璃梁的中点粘性弯曲率来确定玻璃的退火点和应变点。 2. 然而，在与退火和应变点相对应的温度下，玻璃的粘度高度依赖于时间。因此，通过该程序从测量中得出或推断的任何粘度都不能被认为代表平衡结构条件。 1.2 在使用具有已知退火和应变点的标准玻璃束（如国家标准与技术研究所提供和认证的玻璃束）对设备进行直接校准后，应按照规定的程序获得退火点和应变点。 3. 1.3 以公制单位表示的值应被视为标准。括号中给出的值仅供参考。 1.4 本标准并不旨在解决与其使用相关的所有安全问题（如果有的话）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.5 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====== 4.1 本试验方法提供了试验方法的替代程序 C336 用于确定玻璃的退火和应变点。特别建议用于不适合火焰加工的玻璃。它还具有消除纤维伸长法常见的热膨胀和有效长度校正的优点。 4.2 该测试方法提供了有用的数据( 1. )估计应力释放( 2. )制定适当的退火计划，以及( 3. )估算密封件的设定点。因此，它在整个制造、研究和开发过程中得到了广泛的应用。可用于规范验收。

1.1 This test method covers the determination of the annealing point and the strain point of a glass by measuring the rate of midpoint viscous bending of a simply loaded glass beam. 2 However, at temperatures corresponding to the annealing and strain points, the viscosity of glass is highly time-dependent. Hence, any viscosities that might be derived or inferred from measurements by this procedure cannot be assumed to represent equilibrium structural conditions. 1.2 The annealing and strain points shall be obtained following a specified procedure after direct calibration of the apparatus using beams of standard glasses having known annealing and strain points such as those supplied and certified by the National Institute of Standards and Technology. 3 1.3 The values stated in metric units are to be regarded as the standard. The values given in parentheses are for information only. 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 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 ====== 4.1 This test method offers an alternate procedure to Test Method C336 for determining the annealing and strain points of glass. It is particularly recommended for glasses not adaptable to flame working. It also has the advantages that thermal expansion and effective length corrections, common to the fiber elongation method, are eliminated. 4.2 This test method provides data useful for ( 1 ) estimating stress release, ( 2 ) the development of proper annealing schedules, and ( 3 ) estimating setting points for seals. Accordingly, its usage is widespread throughout manufacturing, research, and development. It can be utilized for specification acceptance.