1.1 本试验方法 2. 介绍了用于反光标记和工业用途的玻璃球中真实球体百分比的测定。 1.2 本试验方法包括以下两个程序: 1.2.1 程序A， 在分离成真实球体和不规则颗粒之前，将所选样本分为两个尺寸范围或组，以及 1.2.2 程序B， 在分离之前，将所选样本分为五个尺寸范围或组。 1.2.3 在确定是否符合规范要求时，可以使用程序A或程序B。如果试验表明未达到规定百分比的真实球体和不规则颗粒，则应根据程序B进行仲裁试验。 1.3 以国际单位制表示的数值应视为标准。 括号中给出的值仅供参考。 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 玻璃球的圆度是与其作为反光介质的性能相关的一个可测量方面。 本试验方法的功能是测量与符合适用规范相关的真实球体百分比。 注1: 该方法已用于本试验方法预期范围以外的其他工业领域。

1.1 This test method 2 covers the determination of the percent of true spheres in glass spheres used for retroreflective marking purposes and industrial uses. 1.2 This test method includes two procedures as follows: 1.2.1 Procedure A, in which the selected specimen is split into two size ranges or groups prior to separation into true spheres and irregular particles, and 1.2.2 Procedure B, in which the selected specimen is split into five size ranges or groups prior to separation. 1.2.3 In determining compliance with specification requirements, either Procedure A or Procedure B may be used. Where tests indicate failure to meet the specified percent of true spheres and irregular particles, the referee test shall be made in accordance with Procedure B. 1.3 The values stated in SI 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 The roundness of glass spheres is one measurable aspect relating to their performance as a retroreflective media. The function of this test method is to measure the percent of true spheres as related to compliance with applicable specifications. Note 1: This method has been used in other industrial areas outside the intended scope of this test method.