1.1 这些规程的目的是规定测力仪的校准程序。包括以下类型仪器的程序: 1.1.1 弹力测量仪器，以及 1.1.2 力倍增系统，如天平和小型平台秤。 注1: 通过自重荷载验证也是验证试验机力指示的可接受方法。实践中给出了用于此目的的重量公差 E4类 ; NIST技术说明577中给出了重量校准方法 ( 1. ) 2. ，校准活塞式压力计重量的方法。 1.2 以国际单位制表示的数值应视为标准。 需要时，其他公制和英寸-磅值视为等效值。 1.3 这些规程旨在校准静态测力仪。它不适用于动态或高速力校准，也不能假设根据这些实践执行的校准结果对动态或高速力测量有效。 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 施加和指示力的试验机在许多行业中普遍使用。实践 E4类 旨在为这些机器的力验证提供实践。实践中的必要元素 E4类 是指使用测力仪器，已知其力特性可追溯到SI。 实践 E74 描述如何校准这些测力仪。本程序适用于试验机用户、测力仪器制造商和供应商、提供仪器校准和可追溯性文件的校准实验室、使用测力仪器验证试验机的服务组织以及执行一般结构试验测量的测试实验室。

1.1 The purpose of these practices is to specify procedures for the calibration of force-measuring instruments. Procedures are included for the following types of instruments: 1.1.1 Elastic force-measuring instruments, and 1.1.2 Force-multiplying systems, such as balances and small platform scales. Note 1: Verification by deadweight loading is also an acceptable method of verifying the force indication of a testing machine. Tolerances for weights for this purpose are given in Practices E4 ; methods for calibration of the weights are given in NIST Technical Note 577 ( 1 ) 2 , Methods of Calibrating Weights for Piston Gages. 1.2 The values stated in SI units are to be regarded as the standard. Other metric and inch-pound values are regarded as equivalent when required. 1.3 These practices are intended for the calibration of static force measuring instruments. It is not applicable for dynamic or high speed force calibrations, nor can the results of calibrations performed in accordance with these practices be assumed valid for dynamic or high speed force measurements. 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 Testing machines that apply and indicate force are in general use in many industries. Practices E4 has been written to provide a practice for the force verification of these machines. A necessary element in Practices E4 is the use of force-measuring instruments whose force characteristics are known to be traceable to the SI. Practices E74 describes how these force-measuring instruments are to be calibrated. The procedures are useful to users of testing machines, manufacturers and providers of force-measuring instruments, calibration laboratories that provide the calibration of the instruments and the documents of traceability, service organizations that use the force-measuring instruments to verify testing machines, and testing laboratories performing general structural test measurements.