1.1 本规范涵盖了适用于实验室的精密和通用级玻璃容量瓶的要求。 1.1.1 A类- 每个精度等级的烧瓶应标有字母“A”，以表示符合适用的结构和精度要求。根据制造商的选择，烧瓶可标有识别号（序列号）。 1.1.2 B类- 通用烧瓶的基本设计与A类烧瓶相同。然而，B级烧瓶的体积公差应在A级烧瓶允许的规定范围的两倍以内。 这些烧瓶无需标记其类别名称。 注1: 规格中给出了尺寸为1 mL至25 mL（含）的微型容量瓶的规格 E237 . 注2: 第十二届国际度量衡大会将升重新定义为“立方分米的特殊名称”，但同意允许继续使用升、毫升和毫升这三个术语，除非与最高精度的测量相关。对于容量玻璃器皿，升的新旧含义之间的差异可以忽略不计。 因此，mL或cm 3. 可标记在本规范涵盖的器皿上。 1.1.3 特殊尺寸烧瓶- 精密级烧瓶可采用本标准中未列出的标称容量制造。此类烧瓶应被视为“A级”烧瓶，前提是其满足以下最大“A级”烧瓶的精度公差: 表1 并符合 1.1.1 . 1.1.4 宽口烧瓶- 插入片剂或胶囊以进行分析稀释以及容纳更大直径移液管的要求需要具有更大颈的容量瓶。 这些烧瓶出现在 表2 . 这些烧瓶应符合 1.1.1 . 此外，精度公差应标记在每个“A类”宽口烧瓶上。 1.1.5 特殊尺寸宽口烧瓶- 精密级宽口烧瓶可采用本标准中未列出的标称容量制造。此类烧瓶应被视为“A级”烧瓶，前提是其满足以下最大“A级”宽口烧瓶的精度公差: 表2 以及 1.1.4 . 1.2 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 This specification covers requirements for glass volumetric flasks of precision and general-purpose grades suitable for laboratory purposes. 1.1.1 Class A— Each flask of precision grade shall be marked with the letter “A” to signify compliance with applicable construction and accuracy requirements. Flasks may be marked with an identification number (serial number) at the option of the manufacturer. 1.1.2 Class B— General purpose flasks are of the same basic design as Class A flasks. However, volumetric tolerances for Class B flasks shall be within twice the specified range allowed for Class A flasks. These flasks need not be marked with their class designation. Note 1: Specifications for micro volumetric flasks in sizes from 1 mL to 25 mL, inclusive, are given in Specification E237 . Note 2: The Twelfth General (International) Conference on Weights and Measures redefined the litre as a “special name for the cubic decimetre,” but agreed to permit continuance of the terms litre, millilitre, and mL, except in association with measurements of the highest precision. For volumetric glassware the difference between the old and new meanings of litre is negligible. Therefore, either mL or cm 3 may be marked on ware covered by this Specification. 1.1.3 Special Size Flasks— Precision grade flasks may be manufactured with nominal capacities not listed in this standard. Such flasks shall be considered “Class A” flasks, provided they meet the accuracy tolerance of the next largest “Class A” flask appearing in Table 1 and comply with the marking requirements of 1.1.1 . 1.1.4 Wide-Mouth Flasks— Requirements for insertion of tablets or capsules for assay dilution and to accommodate access of larger diameter pipets require volumetric flasks with larger necks. These flasks appear in Table 2 . These flasks shall conform to the marking requirements of 1.1.1 . Additionally, the accuracy tolerance shall be marked on each “Class A” wide-mouth flask. 1.1.5 Special Size Wide-Mouth Flasks— Precision grade wide-mouth flasks may be manufactured with nominal capacities not listed in this standard. Such flasks shall be considered “Class A” flasks provided they meet the accuracy tolerance of the next largest “Class A” wide-mouth flask appearing in Table 2 and the marking requirements of 1.1.4 . 1.2 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.