1.1 本程序描述了一种测量棒球和垒球动态刚度（DS）和圆柱恢复系数（CCOR）的方法，提供了与蝙蝠球碰撞中观察到的冲击力和球变形类似的冲击力。 1.2 本程序适用于棒球或垒球比赛用球。 1.3 该测试方法基于圆柱测试表面冲击前后的球速测量以及球与冲击表面之间的冲击力。 1.4 以英寸-磅为单位的数值应视为标准值。括号中给出的值是到国际单位制的数学转换，仅供参考，不被视为标准值。 1.5 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。 1.6 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====== 5.1 1钢球动态刚度是钢球硬度的测量值。其测量是为了表示蝙蝠球的冲击力。通过球的重量和速度对其进行归一化，以尽量减少制造和测试变化对测量的影响。 5.2 圆柱恢复系数是由与圆柱表面碰撞引起的相对速度变化的球特性。 5.3 该测试方法比较了棒球和垒球在与圆柱形测试表面碰撞后的性能。 5.4 体育协会可以在官方棒球和垒球的规格中使用DS和CCOR测量值。

1.1 This procedure describes a method of measuring the dynamic stiffness (DS) and cylindrical coefficient of restitution (CCOR) of baseballs and softballs providing similar impact forces and ball deformation as are observed in a bat-ball collision. 1.2 This procedure is for a ball that is intended for the game of baseball or softball. 1.3 The test method is based on ball speed measurements before and after impact with a cylindrical test surface and the impact force between the ball and impacted surface. 1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.5 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. 1.6 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 ====== 5.1 1 The ball dynamic stiffness is a measure of a ball’s hardness. Its measurement is conducted to represent bat-ball impact forces. It is normalized by the ball weight and speed to minimize the influence of manufacturing and test variations from the measure. 5.2 The cylindrical coefficient of restitution is a ball property of relative velocity change caused by impact with a cylindrical surface. 5.3 This test method compares the performance of baseballs and softballs after impact with a cylindrical test surface. 5.4 Sports associations can use DS and CCOR measurements in specifications for official baseballs and softballs.