【国外标准】 Standard Specification for Laboratory Weights and Precision Mass Standards

This specification covers laboratory weights and precision mass standards including their principal physical characteristics and metrological requirements. Maximum permissible error, magnetic property, density, and surface roughness for each weight shall be within the limits indicated in this specification. Physical characteristics shall be based on construction, design, surface area, materials, magnetism, density, surface finish, weight adjustment, and marking.1.1 This specification covers weights and mass standards used in laboratories, specifically classes 000, 00, 0, 1, 2, 3, 4, 5, 6, and 7. This specification replaces National Bureau of Standards Circular 547, Section 1, which is out of print.1.2 This specification and calibration method is intended for use by weight manufacturers, national metrology institutes, weight calibration laboratories, accreditation bodies, users of weights, and regulatory bodies.1.3 This specification contains the principal physical characteristics and metrological requirements for weights that are used.1.3.1 For the verification of weighing instruments;1.3.2 For the calibration of weights of a lower class of accuracy; and1.3.3 With weighing instruments.1.4 Maximum Permissible Errors (formerly 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.1.5 Weight manufacturers must be able to provide evidence that all new weights comply with specifications in this standard (for example, material, density, magnetism, surface finish, mass values, uncertainties) to make any claim of compliance to Specification E617, Maximum Permissible Errors, weight classes, or metrological traceability.1.5.1 During subsequent calibrations, calibration laboratories must meet the requirements of ISO/IEC 17025:2017.1.5.2 Subsequent calibrations must meet all the requirements, including Sections 7, 8, and 9, Table 8 and Table 11 (environmental parameters) to make any claim of compliance to Specification E617, Maximum Permissible Errors, weight classes, or metrological traceability.NOTE 1: Requirements set forth in NIST IR 6969 and NIST IR 5672 are compliant with all the requirements of Specification E617, Sections 7, 8, and 9.1.6 The values stated in SI units are to be regarded as standard.1.7 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.