An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
A locked padlock
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
For his contributions to the development of the NIST Watt Balance, and landmark measurements of the Planck constant, the electron charge, and the Avogadro constant.