1.1 本规程涵盖了制备和测试参考玻璃-金属珠封的程序，以确定玻璃和金属之间热膨胀（或收缩）不匹配的程度。试验按照试验方法进行 F218 （参见第节 2. ). 1.2 本规程适用于所有已建立或实验的玻璃-金属组合，尤其是用于电子元件的玻璃-金属组合。 1.3 设计不匹配测试的实际极限约为300 ppm，超过该极限玻璃可能破裂。 1.4 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户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。 1.5 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====== 4.1 本规程中使用的术语“参考”意味着参考玻璃金属密封件的玻璃和金属均为标准参考材料，如国家标准与技术研究所提供的用于其他物理测试的材料，或二次参考材料，其密封特性已通过标准参考材料的密封件确定（见NIST特别出版物260）。 4. 在NIST制定密封标准参考材料之前，生产商和用户可就二次参考材料达成一致。 5.

1.1 This practice covers procedures for preparing and testing reference glass-to-metal bead-seals for determining the magnitude of thermal expansion (or contraction) mismatch between the glass and metal. Tests are in accordance with Test Method F218 (see Section 2 ). 1.2 This practice applies to all glass-metal combinations, established or experimental, particularly those intended for electronic components. 1.3 The practical limit of the test in devising mismatch is approximately 300 ppm, above which the glass is likely to fracture. 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 The term reference as employed in this practice implies that both the glass and the metal of the reference glass-metal seal will be a standard reference material such as those supplied for other physical tests by the National Institute of Standards and Technology, or a secondary reference material whose sealing characteristics have been determined by seals to a standard reference material (see NIST Special Publication 260). 4 Until standard reference materials for seals are established by the NIST, secondary reference materials may be agreed upon between producer and user. 5