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Mechanical Metrology Program

Summary:

Providing critical measurements of mass, force, vibration, and acoustics for a broad range of industries and aspects of everyday life. Such measurements establish uniformity and reliability for countless products and applications, such as grocery store scales, microphones, pharmaceuticals, and the structural integrity of bridges. The program’s wide-ranging goals include participating in international efforts to redefine the Kilogram, establishing new molecular force standards, improving timeliness and performance of current calibration services, and developing next-generation measurements for acoustics and vibration. Such services help provide industry with the tools needed to maintain or establish the highest levels of competitiveness in world markets.

Description:

NIST has a long history as the nation’s standards keeper for measurements of mass, force, vibration, and other quantities. Precision and accuracy in these measurements are critical for fair and equitable trade, public safety, and innovations in manufacturing across a dramatic range of industrial needs, from pharmaceutical recipes to airplane building, from improved hearing aids to ensuring accurate grocery store scales. But the changing demands imposed by the complexity of new products, as well as the new global economy, require NIST to develop creative approaches to improve its services and develop new ones.

Program technical activities are categorized in three areas that have been defined through discussions with its industrial partners: research and development of measurement techniques to anticipate future needs in measuring mass, acoustics, force, and vibration; provision and continuous improvements of high-quality measurement services; and participation in international activities to facilitate trade through the mutual recognition and acceptance of measurement capabilities and calibration certificates across borders.

The research and development activities include development of the first small force standards based on atomic and molecular interactions; new low-frequency vibration metrology in response to growing industry needs in manufacturing, nuclear power, vehicle ride control, and whole-body vibration control; and new infrasound metrology and standards to address demanding requirements for atmospheric monitoring, scientific studies of the Earth and its environment, and weapons regulatory control. In addition, the program will develop new realization and dissemination methods necessary for NIST to support the proposed redefinition of the Kilogram – the last remaining SI unit defined by an artifact.

The program’s second focus, measurement services activities, include implementing automated and next-generation measurement tools, including mass calibration robots. These efforts will also introduce next-generation calibrations for speakers and microphones, which are needed to establish legal noise standards in the workplace and around air fields, to improve the silence of defense systems, such as submarines, and for a long-standing collaboration with the Department of Veterans Affairs on improving the performance of hearing aids.

Lastly, NIST represents and defends U.S. interests in international standards development and participates in international comparisons to evaluate NIST measurement capabilities and compare them to other countries in order to eliminate trade barriers in the world markets. Only through global agreement on such standards can country-to-country compatibility be guaranteed for a wide range of products.

Major Accomplishments:

  • Completed crucial steps towards a practical method for realization of a new kilogram definition, including development of a stable suspension technique based on magnetic field sensing and servo control, analysis of the effect of magnetic pole shapes on suspension and stability, and stable levitation (less than 1 mg) of 200 g to 1 kg mass artifacts using the new suspension. This will provide the link between the existing artifact-based definition realized in air and the future realization of mass based on fundamental constants in vacuum. This link is essential to guarantee continuity and equivalency of mass measurements.
  • Demonstrated first accurate scheme for practically realizing forces below a nanonewton enabling direct calibration of probes used in single molecule mechanical characterization experiments.
  • Developed reliable methods for performing complex single DNA molecule experiments and achieved the first traceable measurements of this force, therefore demonstrating the use of biological molecules as intrinsic force standards.
  • Demonstrated stable creation and manipulation of single atom chains using a new instrument developed as part of the intrinsic force project. As part of this instrument development, also created a fiber interferometer system for the accurate measurement of picoscale displacements.
  • Completed the development of new measurement system, software, and procedures for reciprocity calibrations of laboratory standard microphones from 31.5 Hz to 20 kHz in plane-wave air-filled couplers. This allows NIST to provide next-generation acoustical measurement services that halves our measurement uncertainties in the most critical frequency range.
  • Completed analysis and final reports of critical key comparisons in the areas of force and vibration metrology where NIST served as pilot laboratory. This guarantees the recognition and validity of the calibration and measurement capabilities of the participating countries under the mutual recognition arrangement (MRA), thereby supporting international trade.
  • Provided critical and state-of-the-art measurement services to the U.S. government and industry through nearly 2000 tests performed
1 kg mass standards made of stainless steel and silicon being calibrated.
1 kg mass standards made of stainless steel and silicon being calibrated.

Start Date:

February 1, 2008

Lead Organizational Unit:

pml

Customers/Contributors/Collaborators:

  • Argonne National Laboratory
  • BIPM
  • Hysitron
  • Veeco
  • Asylum Research
  • MTS Nanotechnology
  • General Motors
  • Ford
  • Dow Chemical
  • DuPont
  • KRISS
  • NPL
  • PTB
  • Worchester Polytechnic Institute (WPI)
  • University of Florida
  • AFMETCAL
  • NASA
  • U.S. Department of Energy
  • OSHA
  • Sandia National Laboratory
  • Rockwell Automation
  • General Motors
  • Raytheon
  • Pratt & Whitney
  • Boeing
  • Lockheed Martin
  • Caterpillar
  • John Deere
  • Endevco
  • Bruel & Kjaer
  • Kistler Instruments
  • Agilent
  • Instron Corporation
  • Interface Inc.
  • HBM Inc.
  • Tovey Engineering, MTS
  • ASTM
  • Morehouse
  • United Technologies
  • Amgen
  • Troemner
  • Mettler-Toledo
  • Los Alamos National Laboratory
  • CENA

Staff:

Dr. Zeina J. Kubarych, Program Manager

Contact

Physical Measurement Laboratory (PML)
Mechanical Metrology Division (681)

General Information:
301-975-6624 Telephone
301-417-0514 Facsimile

100 Bureau Drive, M/S 8221
Gaithersburg, Maryland 20899-8221