MIL-STD-45662A and Calibration



Mil-STD-45662A is a military standard for calibration system requirements. It was fundamental in defining Calibration and Traceability as well as the necessary requirements for an effective calibration program. This would include Environmental Controls, Calibration Intervals, Calibration Procedures, Out-Of-Tolerance conditions, Records keeping, etc.  Sounds very much like ISO 17025.

So where did it go?

NIST Handbook 142(2007) provides a detailed history of the evolution away from MIL-STD-45662A to ISO 17025.

"The NCSL “TQM Committee” became an official ANSI standard writing body (ANSI Committee Z 540) in 1994 and published the U.S. standard as Z540-1-1994. ANSI/NCSL Z540-1-1994 incorporated ISO Guide 25 and MilStd-45662A. Since NCSL published the standard in 1994:

1) the Department of Defense rescinded Mil-Std-45662A in favor of the Z540-1-1994 standard;

2) the NIST National Voluntary Laboratory Accreditation Program (NVLAP) adopted and referenced ANSI/NCSL Z540-1-1994;

3) the American Association for Laboratory Accreditation (A2LA), a private accrediting body, also adopted the standard; and

4) the WMD incorporated the standard into Parts 5 and 6 of the 1996 and 1997 editions of this Handbook. Additional requirements consistent with NVLAP requirements and with the needs of the legal metrology system were included.

In 1997, NIST management made the decision that NIST would operate only one formal accreditation program: the National Voluntary Laboratory Accreditation Program (NVLAP). Therefore, all references to accreditation by WMD were changed to Recognition and WMD ceased issuing Certificates of Accreditation. WMD monitors the level of State compliance to this Handbook and other laboratory quality standards to ensure that adequate accuracy, traceability, and uniformity are maintained in State weights and measures laboratories. In 1999, ISO/IEC Guide 25 was revised and became the international standard ISO/IEC 17025. The 2003 edition of NIST Handbook 143 incorporated revisions to the procedures and general requirements of the NIST Weights and Measures Division (WMD) Measurement Assurance Program for State Laboratory Recognition. The WMD procedures were revised to ensure continued consistency with international standards and guidelines, specifically those currently found in ISO/IEC 17025:1999, General requirements for the competence of testing and calibration laboratories."


Keep it Simple  total calibration management alliance calibration.jpeg


MIL-STD-45662A and ISO 17025 focus on the same functional issues for calibration. This can be broken down into a few simple elements: Management Requirement and Technical Requirements.



Both reference the unbroken chain traceability back to the physical constant.

You might be interested in a FREE resource to assist you in purchasing calibration services from Laboratory Accreditation Bureau.

Download the LAB Guide  for  Purchasing & Evaluating Calibrations

Visit our International Standards used in Calibration page for more on standards used in calibration.


Phil Wiseman

Phil Wiseman

Phil Wiseman is Chief Marketing Officer at Alliance Calibration. He earned a B.S. in Chemical Physics from Centre College. Phil is an ASQ Certified Quality Auditor and ASQ Certified Manager of Quality/Organizational Excellence.

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