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NVLAP Calibration Laboratories LAP

Deadweight Force Machine
A deadweight force machine generally applies forces in compression and tension, derived from the mass of the deadweights, the density of the deadweight material, the density of air and the local acceleration of gravity.


This site has been established for present laboratories and applicants of the accreditation program for calibration laboratories. On this site you will find important program information and links to documents required for successful participation in the program.

Program Description

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 has 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 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

Due to changes in ILAC-P9, ILAC Policy for Participation in Proficiency Testing Activities, NVLAP began to collect proficiency test plans starting with April 2012 renewals.  The content of this plan was not defined at that time.  NVLAP is pending release of a new calibration requirements document that will provide detail.  The term schedule may be more applicable as we really need to know what you have done recently and what you are planning to do.  We have also created a plan and schedule for NVLAP-Coordinated PTs; please see the link below to review this document.  In the future, a periodic review of this will be required as part of maintaining your calibration laboratory accreditation.  Future activity on this page will be:

  • A listing of available PTs that other NVLAP labs have utilized that have been accepted by NVLAP.
  • Clear requirements for proficiency tests at the parameter level.

To view and download the projected schedule of NVLAP-Coordinated Proficiency Testing, please click here.

Frequently Asked Questions (FAQs)

Q: How much does it cost?

A: The current application and annual administrative support fee may be found in our fee schedule. The assessment fee varies with breadth of requested scope and is obtained from a calibration program manager prior to application. Proficiency testing is highly dependent on parameter/uncertainty combinations and needs to be evaluated on a case by case basis. For laboratories in the continental United States*, NVLAP projects and invoices a fixed cost for application, administrative, and assessment. There are no surprises with added costs. There are no fees for requesting changes to scope that do not require another assessment and no added assessment fees for evaluation of your responses.

* Laboratories outside of this area are charged actual costs, which may exceed those based solely on the scope due to additional travel.


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All state labs, all federal labs, and commercial labs U-Z, contact:

Barbara Belzer
Calibration Program Manager
Phone: 301-975-2248
E-mail: barbara.belzer@nist.gov

Commercial labs A-Ins, contact:

Kari Harper
Calibration Program Manager
Phone: 301-975-6612
E-mail: kari.harper@nist.gov

Commercial labs Int-T, contact:

Tom Hettenhouser
Calibration Program Manager
Phone: 301-975-2013
E-mail: thomas.hettenhouser@nist.gov

Any contact can assist you in case of absence.



NCSLI Technical Exchange
February 1-2, 2016 in Jacksonville, FL

NCSLI Workshop and Symposium
July 24-28, 2016 at the St. Paul Convention Center in St. Paul, MN

Link to NCSLI

Calibration Noteworthy

Calibration Scope Changes

NVLAP continues to make improvements to its scopes of accreditation. These changes have occurred recently or will occur upon renewal.  Click here for a complete explanation of NVLAP's calibration scope and NVLAP code modifications.