Mass determination with the magnetic levitation method

Proposal for a new design of electromechanical system

Heikki Kajastie, K. Riski, Alexandre Satrapinski

Research output: Contribution to journalArticleScientificpeer-review

5 Citations (Scopus)

Abstract

The method for realization of the kilogram using 'superconducting magnetic levitation' was re-evaluated at MIKES. The realization of the kilogram based on the traditional levitation method is limited by the imperfections of the superconducting materials and the indefinable dependence between supplied electrical energy and the gravitational potential energy of the superconducting mass. This indefiniteness is proportional to the applied magnetic field and is caused by increasing losses and trapped magnetic fluxes. A new design of an electromechanical system for the levitation method is proposed. In the proposed system the required magnetic field and the corresponding force are reduced, as the mass of the body (hanging from a mass comparator) is compensated by the reference weight on the mass comparator. The direction of the magnetic force can be upward (levitation force, when the body is over the coil) or downward (repulsive force, when the body is under the coil). The initial force to move the body from the coil is not needed and magnetic field sensitivity is increased, providing linearization of displacement versus applied current. This new construction allows a lower magnetic induction, reduces energy losses compared with previous designs of electromechanical system and reduces the corresponding systematic error.
Original languageEnglish
Pages (from-to)298-304
JournalMetrologia
Volume46
Issue number3
DOIs
Publication statusPublished - 2009
MoE publication typeA1 Journal article-refereed

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Magnetic levitation
Magnetic fields
Electromagnetic induction
Systematic errors
Magnetic flux
Potential energy
Linearization
Superconducting materials
Energy dissipation
Defects

Cite this

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title = "Mass determination with the magnetic levitation method: Proposal for a new design of electromechanical system",
abstract = "The method for realization of the kilogram using 'superconducting magnetic levitation' was re-evaluated at MIKES. The realization of the kilogram based on the traditional levitation method is limited by the imperfections of the superconducting materials and the indefinable dependence between supplied electrical energy and the gravitational potential energy of the superconducting mass. This indefiniteness is proportional to the applied magnetic field and is caused by increasing losses and trapped magnetic fluxes. A new design of an electromechanical system for the levitation method is proposed. In the proposed system the required magnetic field and the corresponding force are reduced, as the mass of the body (hanging from a mass comparator) is compensated by the reference weight on the mass comparator. The direction of the magnetic force can be upward (levitation force, when the body is over the coil) or downward (repulsive force, when the body is under the coil). The initial force to move the body from the coil is not needed and magnetic field sensitivity is increased, providing linearization of displacement versus applied current. This new construction allows a lower magnetic induction, reduces energy losses compared with previous designs of electromechanical system and reduces the corresponding systematic error.",
author = "Heikki Kajastie and K. Riski and Alexandre Satrapinski",
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pages = "298--304",
journal = "Metrologia",
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Mass determination with the magnetic levitation method : Proposal for a new design of electromechanical system. / Kajastie, Heikki; Riski, K.; Satrapinski, Alexandre.

In: Metrologia, Vol. 46, No. 3, 2009, p. 298-304.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Mass determination with the magnetic levitation method

T2 - Proposal for a new design of electromechanical system

AU - Kajastie, Heikki

AU - Riski, K.

AU - Satrapinski, Alexandre

PY - 2009

Y1 - 2009

N2 - The method for realization of the kilogram using 'superconducting magnetic levitation' was re-evaluated at MIKES. The realization of the kilogram based on the traditional levitation method is limited by the imperfections of the superconducting materials and the indefinable dependence between supplied electrical energy and the gravitational potential energy of the superconducting mass. This indefiniteness is proportional to the applied magnetic field and is caused by increasing losses and trapped magnetic fluxes. A new design of an electromechanical system for the levitation method is proposed. In the proposed system the required magnetic field and the corresponding force are reduced, as the mass of the body (hanging from a mass comparator) is compensated by the reference weight on the mass comparator. The direction of the magnetic force can be upward (levitation force, when the body is over the coil) or downward (repulsive force, when the body is under the coil). The initial force to move the body from the coil is not needed and magnetic field sensitivity is increased, providing linearization of displacement versus applied current. This new construction allows a lower magnetic induction, reduces energy losses compared with previous designs of electromechanical system and reduces the corresponding systematic error.

AB - The method for realization of the kilogram using 'superconducting magnetic levitation' was re-evaluated at MIKES. The realization of the kilogram based on the traditional levitation method is limited by the imperfections of the superconducting materials and the indefinable dependence between supplied electrical energy and the gravitational potential energy of the superconducting mass. This indefiniteness is proportional to the applied magnetic field and is caused by increasing losses and trapped magnetic fluxes. A new design of an electromechanical system for the levitation method is proposed. In the proposed system the required magnetic field and the corresponding force are reduced, as the mass of the body (hanging from a mass comparator) is compensated by the reference weight on the mass comparator. The direction of the magnetic force can be upward (levitation force, when the body is over the coil) or downward (repulsive force, when the body is under the coil). The initial force to move the body from the coil is not needed and magnetic field sensitivity is increased, providing linearization of displacement versus applied current. This new construction allows a lower magnetic induction, reduces energy losses compared with previous designs of electromechanical system and reduces the corresponding systematic error.

U2 - 10.1088/0026-1394/46/3/018

DO - 10.1088/0026-1394/46/3/018

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SN - 0026-1394

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