### Applications and Limitations of the Kibble-Robinson Theory

April 19, 2024

Author(s)

, , , , John Dragenov, , , ,

Displaying 1 - 25 of 35

April 19, 2024

Author(s)

, , , , John Dragenov, , , ,

February 14, 2024

Author(s)

, , , ,

This paper describes the next generation prototype of the Electronic NIST Torque Realizer (ENTR) project. The first prototype version (ENTR-v1) has been able to realize low-range torques (on the order of 1×10-3 Nm) to uncertainties of less than 1000 parts

May 25, 2023

Author(s)

, , , , Charles Waduwarage Perera, ,

The United States National Institute of Standards and Technology (NIST) has been developing a new device for primary standard realization of torque utilizing established trace- ability to the quantum-electrical International System of Units (SI) standards

December 10, 2022

Author(s)

, , , , , , , , , , ,

The revision of the International System of Units (SI) on May 20th, 2019, has enabled new improved experiments to consolidate and simplify electrical and mechanical metrology currently underway. Historically within the SI, the definition of energy was only

October 22, 2022

Author(s)

, , , , , Shisong Li

Analytically the force and torques on a coil in a field of magnetic flux density can be calculated one of two ways. The line integral can be conducted along the coil's wire, summing up the differential force contribution. For each differential line segment

June 20, 2022

Author(s)

, , , , 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

June 3, 2022

Author(s)

, , , , , , ,

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

February 18, 2022

Author(s)

, , ,

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

August 22, 2020

Author(s)

, , , , , ,

August 22, 2020

Author(s)

, , , , ,

August 22, 2020

Author(s)

, , , , , ,

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

May 23, 2019

Author(s)

, , , , ,

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

March 20, 2019

Author(s)

, , ,

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

July 28, 2017

Author(s)

, , , , , , ,

Researchers at the National Institute of Standards and Technology(NIST) estimate the value of the Planck constant as h = 6.62606994(10) x 10^-34 Js, hence with relative standard uncertainty 15.3 x 10^-9. This measurement result is based on over 17,000

September 28, 2016

Author(s)

, , , Shisong Lee, , , ,

Using a watt balance and a frequency comb, a mass-energy equivalence is derived. The watt balance compares mechanical power measured in terms of the meter, the second, and the kilogram to electrical power measured in terms of the volt and the ohm. A direct

September 1, 2016

Author(s)

,

In 2018, the International System of Units (SI) is expected to undergo a complete redefinition. This redefinition presents a paradigm shift where the present SI, based on seven fundamental units, will evolve into a system based on seven fundamental

July 26, 2016

Author(s)

, , , , , , , ,

Measurements of the Planck constant with watt balances using 1 kg masses have achieved relative standard uncertainties below 2 x 10-8. Having established a metrological link between the kilogram and this fundamental constant of nature, a redefinition of

July 10, 2016

Author(s)

, , , , ,

In the past four years, we have constructed a new watt balance at the National Institute of Standards and Technology (NIST), with the goal to realize the unit of mass after the redefinition of the International System of Units, expected to occur in 2018

June 21, 2016

Author(s)

, , , , , , , Shisong Li

A precise instrument, called a watt balance, compares mechanical power measured in terms of the meter, the second and the kilogram to electrical power measured in terms of the volt and the ohm. A direct link between mechanical action and the Planck

February 10, 2016

Author(s)

, Shisong Li, , , ,

A watt balance is a precision apparatus for the measurement of the Planck constant that has been proposed as a primary method for realizing the unit of mass in a revised International System of Units. In contrast to an ampere balance, which was

October 20, 2015

Author(s)

, , , , , , , , Xiang Zhang

A redefinition of our system of units, the SI, is currently being discussed and its implementation is expected in 2018. With the redefinition, the current base units will no longer be required and all units henceforth will be based upon fixed values of

March 31, 2015

Author(s)

, , , , , , ,

In early 2014, construction of a new watt balance, named NIST-4, has started at the National Institute of Standards and Technology (NIST). In a watt balance, similar to a mass comparator, the gravitational force of an unknown mass is compensated by an

February 5, 2015

Author(s)

, , , , , , ,

Researchers at the National Institute of Standards and Technology have been using a watt balance, NIST-3, to measure the Planck constant h for over ten years. Two recently published values disagree by more than one standard deviation. The motivation for

January 21, 2015

Author(s)

, Eric J. Leaman, , , , , ,

A new watt balance is being constructed at the National Institute of Standards and Technology in preparation for the redefinition of the International System of Units and the realization of mass through an exact value of the Planck constant. The total

November 9, 2014

Author(s)

, , , , , , , ,

NIST recently used a watt balance instrument known as NIST-3 to measure the Planck constant in terms of IPK with a relative uncertainty of approximately 45 parts in 10e9. Along the way to this new NIST value of h, the instrument was also employed to