State Weights and Measures Laboratories Program Handbook (NIST Handbook)

the long version

This Handbook describes the procedures followed in evaluating State (and a few other jurisdictional) legal metrology laboratories for competence. To be formally Recognized, a laboratory must satisfy general and technical requirements for each measurement area in which recognition is desired (see Appendix B). This program is managed by the WMD. The general requirements in sections 4 and 5 incorporate ISO/IEC 17025:2005 (as adopted by the NVLAP Calibration Laboratories Accreditation Program) and address internationally accepted quality management practices for calibration and testing laboratories. In addition to ISO/IEC 17025 and NVLAP requirements, sections 4 and 5 contain additional general requirements as “notes” that are specific for State legal metrology laboratories. (See Section 7, References.) The technical criteria in Section 6 amplify general criteria (ISO/IEC 17025) for each specific measurement parameter to be used as needed. Technical requirements of the WMD recognition program are nearly identical to the NVLAP guidelines published in the NIST/NVLAP Handbook 150-2F (Dimensional) and 150-2G (Mechanical), Calibration Laboratories Technical Guides; however, while WMD does not operate a formal accreditation program it does use the technical section as requirements rather than as guidelines. The technical requirements include demonstration that: 1) suitable test equipment, calibration standards, defined test procedures, and the general facilities necessary for good metrological services are available; and 2) that staff have a comprehensive understanding of calibration, measurement, and test requirements and are capable of applying them.