Skip to main content
U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.


Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Fundamental Electrical Measurements Group

The Fundamental Electrical Measurements group supports the nation's infrastructure by providing calibration services in the general areas of resistance and impedance. As part of this mission, the group maintains an active research program in precision measurements based on fundamental constants in the development of quantum electrical standards.

The FEM group uses physical laws, quantum invariants, and ultra-precision measurement techniques to create and refine a core set of experiments used as the US national standards for the ohm, farad, and, in the near future, the kilogram. The group strives to improve the accessibility, reliability, precision, accuracy, and range of values that can be achieved and disseminated from each standard by advancing the state of the art in optical, mechanical, and, of course, electrical systems used in the realization of these units.

News and Updates

Projects and Programs

Quantum Conductance

Graphene, the two-dimensional honeycomb carbon lattice isolated in 2004, has enabled significant advancement in a variety of subfields in physics due to its

Electronic Kilogram

This project provides the basis for a new definition of mass, based on unchanging quantum properties of nature rather than a physical artifact. This is

Farad and Impedance Metrology

This project aims to provide the world's best basis for accurate impedance measurements by tying the U.S. legal system of electrical units to the International

Metrology of the Ohm

Resistance standards traceable to NIST provide references for measurements of current at levels from 3000 A to below 20 fA and are used to support a wide


Gravity measured with record precision

Stephan Schlamminger
The gravitational constant G describes the strength of the gravitational uncertainty. Two new measurements with the world's smallest uncertainties are reported.


Jon Pratt Elected ASPE Fellow

Those eligible as candidates for election to Fellows shall be members who have contributed to the advancement of precision engineering by...

2017 APS Fellow - David Newell

The criterion for election is exceptional contributions to the physics enterprise; e.g., outstanding physics research, important...


Group Leader