Electrical, Mass, and Force Metrology

Objectives: We seek to advance metrology, the science of measurement, and provide the foundation for accurate units of measure for electrical, mass, and force quantities across all scales with the highest precision possible. Our goal is to realize all primary units of measure using first-principles physics, the atomic basis of time, and physical invariants, and to disseminate them to meet the measurement needs of the Nation and to support the global competitiveness of U.S. industry. [1].

Intended Outcome and Background

We create foundational science and technology that provides the basis of the infrastructure for accurate and reliable measurements in the U.S. We conceive and execute the "hero" experiments necessary to link the quantum and classical world, so that NIST electrical, mass, and force reference standards and measurement services – and all the physical standards at NIST that depend on them (temperature, pressure, etc.) – can effectively and reliably support America's academic, security, strategic, and economic interests. In fulfilling NIST's Constitutional mandate to provide standard weights and measures, our primary outcome is world-leading measurement infrastructure that continuously improves as new science and associated technologies emerge to facilitate U.S. security, competitiveness, and leadership in the global economy.

If you need to steer electron beams in the National Synchrotron Light Source to examine the properties of next-generation nanomaterials, or create a Smart Grid to enable greater efficiencies and more renewable energy resources in the Nation's electric power system, or weigh the contents of every container entering or leaving the United States to establish shipping costs –and want to have absolute confidence in the results – then you will ultimately trace your data to a unit of measure based on our work in electrical, mass, and force metrology.

In order to support this wide range of U.S. measurement needs, our activities extend from experiments that exploit quantum mechanics to directly achieve a unit of measure, such as NIST's graphene quantum Hall resistance device [2], to experiments that mix quantum and classical physics, such as the NIST watt [3] and electrostatic force balances [4] which aim to replace the kilogram standard unit of mass with amore universal and stable one based on electrical measurement. Our work includes applied research that invents or refines technologies for effectively disseminating the units, such as the NIST magnetically levitating balance [5] for disseminating the unit of mass from vacuum to air, electrical standards and techniques for disseminating the ohm over 20 orders of magnitude [6], and reference standards to quantify electrical power and voltage, such as AC/DC thermal converters [7].

Highlights and Accomplishments

[1] SI Redefinition Portal

[2] Quantum Conductance

[3] Electronic Kilogram

[4] Small mass and force metrology at NIST

[5] Disseminating the Kilogram, no strings attached

[6] Metrology of the ohm

[7] New AC voltage devices