NIST logo

Laboratory Metrology Program


The OWM Laboratory Metrology Program provides the basis for ensuring traceability of state weights and measures standards to NIST. It also conducts Fundamentals of Metrology, Mass, Volume and Advanced Mass training for metrologists from the states, industry, and other countries.

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).

By selecting these links, you will be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to OWM-webmaster

SOP 18/19 Calibration of Open Neck Field Standard Test Measures

See the new video podcast of a calibration of a 5 gal graduated neck test measure.

Please download and read SOP 18 and 19 prior to viewing.


General Information:
301-975-4004 Telephone
301-975-8091 Facsimile

100 Bureau Drive, M/S 2601
Gaithersburg, MD 20899-2601