THE CONSTRUCTION AND CHARACTERIZATION OF THE NIST-4 PERMANENT MAGNET SYSTEM

Published

November 9, 2014

Author(s)

Leon S. Chao, Frank C. Seifert, Shisong Li, Darine El Haddad, Stephan Schlamminger, Jon R. Pratt

Abstract

A watt balance is an electromagnetic force balancing instrument to realize the unit of mass at the kilogram level. The magnet system is one of the key components. Our group at the National Institute of Standards and Technology is currently building a next-generation, permanent-magnet driven watt balance, NIST-4. We describe the construction of the magnet system, characterization of the field profile, and adjustment methods used to achieve an ideal magnetic field profile. Although the absolute field strength is not critical, the uniformity of the magnetic flux profile through the air gap of the magnet is essential for a watt balance experiment.

Proceedings Title

ASPE Annual Meeting Proceedings

Conference Dates

November 3-7, 2014

Conference Location

Boston, MA

Pub Type

Conferences

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Keywords

watt balance, magnet, NIST-4, magnetic flux, metrology

Citation

Chao, L. , Seifert, F. , Li, S. , El, D. , Schlamminger, S. and Pratt, J. (2014), THE CONSTRUCTION AND CHARACTERIZATION OF THE NIST-4 PERMANENT MAGNET SYSTEM, ASPE Annual Meeting Proceedings, Boston, MA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=916530 (Accessed October 9, 2025)