1.1本规范涵盖实验室中使用的各类重量和质量标准。不包括用于商业测量的重量，但包括一类用于校准商业测试重量的标准。描述了每一类的公差和设计限制，以便可以为适当的应用选择单个权重或权重集（见注释）。一般来说，本规范在功能上取代了已绝版的国家标准局第547号通知第1节。 注:尽管公制重量几乎仅用于实验室，但本规范中给出了所有类别的非公制重量的公差，采用美国惯用单位。预计随着计量（即使在测试实验室）的进一步进行，本规范中给出的非计量表将过时。 1.2本规范认可第1号国际建议（平均精度为1 g至10 kg的圆柱重量）和第20号国际建议（精度等级E1、E2、F1、F2和 M1 从50 kg到1 mg）。在适当情况下，建议使用这些国际建议。

1.1 This specification covers various classes of weights and mass standards used in laboratories. Weights used for commercial measurements are excluded, except that one class of standards designed for the calibration of commercial test weights is included. Tolerances and design restrictions for each class are described in order that both individual weights or sets of weights can be chosen for appropriate applications (see Note). In general, this specification replaces, in function, National Bureau of Standards Circular 547, Section 1, which is out of print. Note-Although metric weights are almost exclusively used in laboratories, tolerances are given in this specification for nonmetric weights in U.S. customary units for all classes. It is anticipated that as metrication, even in test laboratories, proceeds further, the nonmetric tables given in this specification will become obsolete. 1.2 This specification recognizes International Recommendation No. 1 (cylindrical weights from 1 g to 10 kg of average precision) and International Recommendation No. 20 (weights of classes of precision E1, E2, F1, F2, and M1 from 50 kg to 1 mg). Where appropriate, it is recommended that these International Recommendations be used.