1.1 本指南涵盖了使用流动流数字分析仪测定路面标线系统中使用的玻璃球的圆度。AASHTO M247中定义了路面标线系统的典型等级，范围从0到5。 1.2 本指南规定了按照机构路面标线材料规范的要求，以各种格式呈现圆度数据。对于大多数规范，标准格式是将圆度数据表示为相对于一系列标准ASTM筛孔尺寸的真实球体百分比。 1.3 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 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 玻璃微珠的圆度对路面标线系统的反光效率有重大影响。 4.2 本指南用于表征玻璃微珠的圆度，以便根据路面标线应用中玻璃微珠的标准规范进行符合性测试。 4.3 虽然本指南在测量路面标线玻璃珠的圆度之外还有潜在的工业应用，但这些都超出了本标准的范围。

1.1 This guide covers the determination of the roundness of glass spheres used in pavement marking systems using a flowing stream digital analyzer. Typical gradations for pavement marking systems are defined in ranges from Type 0 through 5 in AASHTO M247. 1.2 This guide provides for the presentation of roundness data in a variety of formats to the requirement of the agency pavement marking material specification. For most specifications the standard format is to present the roundness data as Percent True Spheres relative to a series of standard ASTM sieve sizes. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 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 beads has a significant influence on the retroreflective efficiency of a pavement marking system. 4.2 The guide is for the characterization of the roundness of glass beads for the purpose of compliance testing against standard specification for glass beads in pavement marking applications. 4.3 While there are potential industrial applications for this guide beyond the measurement of roundness of glass beads for pavement markings, those are beyond the scope of this standard.