1.1 测试方法中描述了用于测量玻璃应力的旋光仪和偏光镜 F218 , C148 和 C978 . 这些仪器包括一个光源和几个光学元件（偏振器、光学延迟器、滤波器等），需要偶尔清洁、重新校准和校准。这些实践的目的是描述维持这些仪器校准所需的校准和验证程序，并确保光学设置在符合要求的测量规范范围内。 1.2 在这些实践中，必须由完全理解应力延迟测量中使用的概念并在测试方法中描述的测量程序实践中有经验的合格人员进行验证和校准 F218 , C148 和 C978 . 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。

1.1 Polarimeters and polariscopes used for measuring stress in glass are described in Test Methods F218 , C148 , and C978 . These instruments include a light source and several optical elements (polarizers, optical retarders, filters, and so forth) that require occasional cleaning, realigning, and calibration. The objective of these practices is to describe the calibration and verification procedures required to maintain these instruments in calibration and ensure that the optical setup is within specification for satisfactory measurements. 1.2 It is mandatory throughout these practices that both verification and calibration are carried out by qualified personnel who fully understand the concepts used in measurements of stress retardation and are experienced in the practices of measuring procedures described in Test Methods F218 , C148 , and C978 . 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 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.