Calibration LAP

The Calibration Laboratories Accreditation Program (LAP) was developed by the National Voluntary Laboratory Accreditation Program (NVLAP) at the National Institute of Standards and Technology (NIST) as a result of interest from private industry and at the request of the National Conference of Standards Laboratories (now the NCSL International). The goal of the program is to provide a means by which calibration laboratories can be assessed for competency. This voluntary program is not designed to serve as a means of imposing specific calibration procedures or minimum uncertainties on applicant laboratories; instead, the program allows for all scientifically valid calibration schemes and requires that laboratories derive and document their measurement uncertainties.

The program offers accreditation in 8 major fields of metrology with over 90 individual parameters. Laboratories' uncertainties range from working level to values equivalent to NIST. Our assessor base includes both world-renowned NIST experts in the various parameters and experts from industry. The program insures laboratories are assessed by personnel experienced in the specific parameter at, or in most cases above, the level at which the laboratories are operating. 

Proficiency Testing Requirements

For those measurement parameters where it is available, participation is mandatory in an appropriately rigorous PT (testing at the level of the laboratory’s accredited capabilities).

NVLAP accepts proficiency test results from an accredited laboratory when:

a) The PT provider is accredited to ISO/IEC 17043 for the parameter being tested at the uncertainty level of that test, and that the accreditation to ISO/IEC 17043 is issued by a body which is signatory to a mutual recognition arrangement (MRA) for proficiency testing accreditation in a regional body recognized by the International Laboratory Accreditation Cooperation (ILAC).

b) The PT is coordinated through the NIST Office of Weights and Measures (OWM) Regional Measurement Assurance Program (RMAP)

c)The PT or Measurement Assurance Program (MAP) is offered through a NIST technical division.

See the current version of NIST Handbook 150-2 for additional guidance.

Requirements Documents

• NIST Handbook 150:2020, update 1, NVLAP Procedures and General Requirements
• NIST Handbook 150-2:2024, NVLAP Calibration Laboratories
• Lab Bulletin LB-158-2024, Release of NIST Handbook 150-2, 2024 Edition
• Lab Bulletin LB-117-2020, Update to NVLAP accreditation documents for laboratories accredited to ISO/IEC 17025:2017 under the ILAC MRA

References and Information

International Laboratory Accreditation Cooperation (ILAC)

• ILAC Policy Documents
• ILAC Guidance Documents

National Conference of Standards Laboratories (NCSLI)

• NCSLI Recommended Practices (RPs)
• NCSLI Laboratory Management (LMs)

National Institute of Standards and Technology (NIST)

• NIST TN 1297 - Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results
• NIST SP 330 - The International System of Units (SI)
• NIST SP 811 - Guide for the Use of the International System of Units (SI)
• NISTIR 6969 - GLP 9, Good Laboratory Practice for Rounding Expanded Uncertainties and Calibration Values
• NIST HB 143-2023 - NIST Office of Weights and Measures (OWM) Recognition Program Handbook, 7th Edition

International Bureau of Weights and Measures (BIPM)

• BIPM Publications BIPM Key Comparison Database (KCDB)