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Physical Measurement Laboratory

PML is a world leader in the science of measurement. We determine the definitive methods for nearly every kind of measurement employed in commerce and research, provide «޲Ʊ-traceable calibrations, and disseminate standards and best practices throughout the nation. At the same time, PML works continuously at the outermost frontiers of metrology, devising tools and techniques to meet the ever-changing demands of American industry and science.

SI Redefinition

Outer circle has one wedge for each of the 7 SI units (kilogram, meter, second, ampere, kelvin, mole, and candela) and the inner circle has wedges for the 7 important constants.
Credit: BIPM

«޲Ʊ is producing a series of special reports on the worldwide consensus plan to redefine four of the seven basic units of measurement in the International System of Units in terms of invariants of nature.

Explore these stories, as they become available, on the SI Redefinition Portal.

News and Updates

What Laser Color Do You Like?

Researchers at the National Institute of Standards and Technology («޲Ʊ) and the University of Maryland have developed a microchip technology that can convert

Events

5615: Mass Metrology Seminar

Mon, Oct 19 - Fri, Oct 30 2020
The Mass Metrology Seminar is a two-week, "hands-on" seminar. It incorporates approximately 30 percent lectures and 70

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

Nanolithography Design Tools

Accurate production of nanoscale features on semiconductor chips is essential to their performance, but typical design tools cater to the dominance of straight

High-Power Lasers for Manufacturing 

Measuring the intensity of high-power lasers used by manufacturers for precision cutting and welding can be difficult due to large instrumentation challenges

Brain Mapping Technologies

Magnetic signals produced by electrical currents in the brain can be used to map brain processes and help in the diagnosis and treatment of disease

Awards

Press Coverage

Combing a Herd for Methane Emissions

American Physical Society
Specialized light beams called frequency combs could help detect greenhouse-gas emissions from livestock with greater precision than existing methods.

A more perfect unit: the new mole

Popular Science
A video about the redefinition of the mole, featuring «޲Ʊ's Savelas Rabb, Robert Vocke, and Stephan Schlamminger.

Contacts

PML Director and PML Deputy Director

Associate Director for Measurement Services and Associate Director

Executive Secretaries to Director Kushmerick and Deputy Director Williams