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Search Publications by: Stephan Schlamminger (Fed)

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Displaying 26 - 50 of 88

Design of an electrostatic feedback for an experiment to measure G

June 20, 2022
Author(s)
Stephan Schlamminger, Leon Chao, Vincent Lee, David B. Newell, Clive Speake
The torsion pendulum at the heart of the BIPM apparatus to measure the gravitational constant, $G$, is used to measure the gravitational torque between source and test-mass assemblies with two methods. In the Cavendish method, the pendulum moves freely. In

A New Spin on Kibble: A Self Calibrating Torque Realization Device at NIST

June 3, 2022
Author(s)
Zane Comden, Stephan Schlamminger, Charles Waduwarage Perera, Frank Seifert, David B. Newell, Jay H. Hendricks, Barbara L. Goldstein, Leon Chao
After the 2019 redefinition of the International System of Units (SI), torque no longer needs to be traceable to a calibrated weight suspended from a known lever arm. Specifically, a modification of the Kibble principle used for realizing the kilogram

The irony of the magnet system for Kibble balances -- a review

March 1, 2022
Author(s)
Stephan Schlamminger, Shisong Lo
The magnet system is an essential component in the Kibble balance, supplying the magnetic flux that plays a vital role as the geometric factor $Bl$. Ironically, the $Bl$ factor cancels out and does not appear in the final Kibble equation. Nevertheless

The Crane Operator's Tricks and other Shenanigans with a Pendulum

February 18, 2022
Author(s)
Stephan Schlamminger, Leon Chao, David B. Newell, Vincent Lee
The dynamics of a swinging payload suspended from a stationary crane can be described as a simple pendulum, typically an unwelcome phenomenon on a construction site. An experienced crane operator can deliver a swinging payload and stop dead on target in a

Evaluations of a Detector-Limited Digital Impedance Bridge

April 6, 2021
Author(s)
Mona Feige, Stephan Schlamminger, Yicheng Wang
We tested a simple digital impedance bridge using two nominally equal resistors to form a 1:1 ratio. We focused on resolution and stability of the detectors. Fluctuations of the source voltages were largely removed through postprocessing of the digitized

Design of an electrostatic balance to measure optical power of 100 kW

February 19, 2021
Author(s)
Lorenz Keck, Gordon A. Shaw, Renee Theska, Stephan Schlamminger
To accommodate the need for increased portability and accuracy in laser power measurement instrumentation above 100 Watt at the National Institute of Standards and Technology (NIST), a new instrument is required. This instrument is intended to create a new

Gravity measured with record precision

February 10, 2021
Author(s)
Stephan Schlamminger
The gravitational constant G describes the strength of the gravitational uncertainty. Two new measurements with the world's smallest uncertainties are reported.

Redefining the kilogram and other SI units

February 10, 2021
Author(s)
Stephan Schlamminger
Units are at the heart of science and technology. Most measurements require units to express their result. The International System of Units (SI) provides a widely used coherent framework of units. While the present SI is fit for purpose for all

Resolution of the paradox of the diamagnetic force on the Kibble coil

January 13, 2021
Author(s)
Stephan Schlamminger, Shisong Li, Rafael Marangoni, Darine El Haddad, Qing Wang, Wei Zhao
Employing very simple electro-mechanical principles known from classical physics, the Kibble balance establishes a very precise and absolute link between quantum electrical standards and macroscopic mass or force measurements. The success of the Kibble

The Design of an Instrument to Realize Small Torque at NIST

August 22, 2020
Author(s)
Leon S. Chao, Rafael Marangoni, Frank C. Seifert, Darine El Haddad, Jon R. Pratt, David B. Newell, Stephan Schlamminger
After the recent redefinition of the International System of Units (SI), torque no longer needs to be traceable to a calibrated mass in a gravitational field suspended from a known lever arm and disseminated through a chain of torque transducers.An SI

Basic Metrology for 2020

April 30, 2020
Author(s)
Stephan Schlamminger, Richard Davis
2019 was a big year for Metrology. The international system of units was revised on World Metrology Day, May 20th, that year [1]. What will 2020 bring? In this article we discuss five promising advances that we have on a watchlist for 2020. First, we

The Design and Development of a Tabletop Kibble Balance at NIST

May 23, 2019
Author(s)
Leon S. Chao, Frank C. Seifert, Darine El Haddad, Julian Stirling, David B. Newell, Stephan Schlamminger
On November 16, 2018, the 26th General Conference on Weights and Measures (CGPM) voted unanimously to revise the International System of Units (SI) from a system built on seven base units to one built on seven defining constants and will officially become

The Kibble balance and the kilogram

March 25, 2019
Author(s)
Stephan Schlamminger, Darine El Haddad
Dr. Bryan Kibble invented the watt balance in 1975 to improve the realization of the unit for electrical current, the ampere. With the discovery of the Quantum Hall e ect in 1980 by Dr. Klaus von Klitzing and in conjunction with the previously predicted

The Design and Development of a Tabletop Kibble Balance at NIST

March 20, 2019
Author(s)
Leon S. Chao, Frank C. Seifert, Darine El Haddad, Stephan Schlamminger
A global paradigm shift to redefine the International System of Units (SI) from a system based on seven fundamental units to seven fundamental constants is well under way. More specifically, the unit of mass, the kilogram, will be realized via a fixed

A new magnet design for future Kibble balances

April 4, 2018
Author(s)
Stephan Schlamminger, Shisong Li, Michael Stock
We propose a new permanent magnet system for Kibble balance experiments, which combines advantages of the magnet designs invented by the National Physical Laboratory (NPL) and by the Bureau International des Poids et Mesures (BIPM). The goal of the

Measurements of the Newtonian Constant of Gravitation, G

November 30, 2017
Author(s)
Christian Rothleitner, Stephan Schlamminger
The Newtonian Constant of Gravitation G seems to be the fundamental constant that is most difficult to measure accurately. In the past three decades more than a dozen precision measurements were performed. Unfortunately the scatter of the data points is

Contributions of precision engineering to the revision of the SI

November 28, 2017
Author(s)
Stephan Schlamminger, Harald Bosse, Horst Kunzmann, Jon R. Pratt, Ian Robinson, Michael de Podesta, Paul Shore, Paul Morantz
All measurements performed in science and industry are based on the International System of Units, the SI. It has been proposed to revise the SI following an approach which had already been implemented for the redefinition of the unit of length, the metre
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