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Laboratory Metrology Program

The OWM Laboratory Metrology Program provides the basis for ensuring traceability of state weights and measures standards to the International System of Units (SI) through NIST.

State legal metrology laboratories are custodians at the State level of measurement standards that serve as the basis for ensuring equity in the marketplace and as reference standards for calibration services for indigenous industry. As part of its program to encourage a high degree of technical and professional competence in such activities, the National Institute of Standards and Technology (NIST) Office of Weights and Measures (OWM) has developed performance standards and formalized procedures for Recognition of State legal metrology laboratories on a voluntary basis. Certificates of Metrological Traceability are issued upon evaluation of the laboratory's ability to make reliable metrological measurements (principally mass, volume, length, and temperature).
The OWM Laboratory Metrology Program consists of six formal Regional Measurement Assurance Program (RMAP) groups as shown in this map. The RMAPS include the Caribbean Measurement Assurance Program (CaMAP), the Southwestern Assurance Program (SWAP), the Southeastern Measurement Assurance Program (SEMAP), the Northeastern Measurement Assurance Program (NEMAP), the MidAmerica Measurement Assurance Program (MidMAP), and the Western Regional Assurance Program (WRAP). Participants include weights and measures laboratories and other government laboratories, such as Los Angeles County (LAC) and the U.S. Department of Agriculture, Grain Inspection Packers and Stockyards Administration (USDA-GIPSA).

Lab Metrology Resources

  1. Calibration Services
  2. Engineering Metrology Toolbox
  3. Fluid Flow Group (& Volume)
  4. Laboratory Accreditation Program/NVLAP
  5. Length
  6. Mass and Force Group
  7. SI Units, Uncertainties
  8. Statistical Engineering, Electronic Statistics Handbook
  9. Thermometry and Humidity
  10. Traceability Resources
  11. Weights and Measures Publications


5827 Mass Metrology Seminar

Mon, Feb 6 - Fri, Feb 17 2023
The Mass Metrology Seminar is a two-week, "hands-on" seminar. It incorporates approximately 30 percent lectures and 70

5840 Fundamentals of Metrology

Mon, Feb 27 - Fri, Mar 3 2023
The 5-day Fundamentals of Metrology seminar is an intensive course that introduces participants to the concepts of

Industry Impacts

Fare Standards for Rideshare Services

To calculate fares, app-based ride services such as Lyft and Uber don’t use traditional taxi meters, but instead combine data from GPS and cellular networks to


Press Coverage


General Information: