Investigation on the Noise Separation in Watt Balance Experiments

2008 ◽  
Vol 381-382 ◽  
pp. 619-622
Author(s):  
W. Zeng ◽  
Xiang Qian Jiang ◽  
P. Scott ◽  
L. Blunt
Keyword(s):  
Background Noise ◽  
International System ◽  
Histogram Method ◽  
Stationary Noise ◽  
Vibration Data ◽  
System Of Units ◽  
Environmental Vibration ◽  
Transient Events ◽  
Watt Balance ◽  
Definition Of

The detection of stationary and non-stationary noise in environmental vibration data is an important issue when considering the precision of the Watt balance, an electromechanical apparatus for the new definition of the kilogram in the international system of Units (SI). In this paper, the authors propose a frequency histogram method to find the structure of the stationary noise from large amount of datasets. For the non-stationary noise, the authors propose a wavelet based denoising methods to distinguish the transient events from the background “noise”, to find their duration and content and to identify their location in time.

scholarly journals The watt balance: determination of the Planck constant and redefinition of the kilogram

2011 ◽  
Vol 369 (1953) ◽  
pp. 3936-3953 ◽  
Author(s):  
M. Stock
Keyword(s):  
International System ◽  
Accurate Determination ◽  
Electrical Power ◽  
Planck Constant ◽  
System Of Units ◽  
Macroscopic Quantum Effects ◽  
Watt Balance ◽  
Definition Of ◽  
Base Units

Since 1889, the international prototype of the kilogram has served as the definition of the unit of mass in the International System of Units (SI). It is the last material artefact to define a base unit of the SI, and it influences several other base units. This situation is no longer acceptable in a time of ever-increasing measurement precision. It is therefore planned to redefine the unit of mass by fixing the numerical value of the Planck constant. At the same time three other base units, the ampere, the kelvin and the mole, will be redefined. As a first step, the kilogram redefinition requires a highly accurate determination of the Planck constant in the present SI system, with a relative uncertainty of the order of 1 part in 10 8 . The most promising experiment for this purpose, and for the future realization of the kilogram, is the watt balance. It compares mechanical and electrical power and makes use of two macroscopic quantum effects, thus creating a relationship between a macroscopic mass and the Planck constant. In this paper, the operating principle of watt balance experiments is explained and the existing experiments are reviewed. An overview is given of all available experimental determinations of the Planck constant, and it is shown that further investigation is needed before the redefinition of the kilogram can take place. Independent of this requirement, a consensus has been reached on the form that future definitions of the SI base units will take.

scholarly journals Thermodynamic Properties of Seawater, Ice and Humid Air: TEOS-10, Before and Beyond

2018 ◽  
Author(s):  
Rainer Feistel
Keyword(s):  
Hydrological Cycle ◽  
International System ◽  
Metrological Traceability ◽  
Humid Air ◽  
Ongoing Research ◽  
Seawater Salinity ◽  
System Of Units ◽  
Atmospheric Relative Humidity ◽  
Definition Of ◽  
First Time

Abstract. In the terrestrial climate system, water is a key player in the form of its different ambient phases of ice, liquid and vapour, admixed with sea salt in the ocean and with dry air in the atmosphere. For proper balances of climatic energy and entropy fluxes in models and observation, a highly accurate, consistent and comprehensive thermodynamic standard framework is requisite in geophysics and climate research. The new “Thermodynamic Equation of Seawater – 2010” (TEOS-10) constitutes such a standard for properties of water in its various manifestations in the hydrological cycle. TEOS-10 has been recommended internationally in 2009 by the Intergovernmental Oceanographic Commission (IOC) to replace the previous 1980 seawater standard, EOS-80, and in 2011 by the International Union of Geodesy and Geophysics (IUGG) “as the official description for the properties of seawater, of ice and of humid air”. This paper briefly reviews the development of TEOS-10, its novel axiomatic properties, new oceanographic tools it offers, and important tasks that still await solutions by ongoing research. Among the latter are new definitions and measurement standards for seawater salinity and pH, in order to establish their metrological traceability to the International System of Units (SI), for the first time after a century of widespread use. Of similar climatological relevance is the development and recommendation of a uniform standard definition of atmospheric relative humidity that is unambiguous and rigorously based on physical principles.

scholarly journals The kelvin redefinition and its mise en pratique

2016 ◽  
Vol 374 (2064) ◽  
pp. 20150037 ◽  
Author(s):  
B. Fellmuth ◽  
J. Fischer ◽  
G. Machin ◽  
S. Picard ◽  
P. P. M. Steur ◽  
...  
Keyword(s):  
International System ◽  
Thermodynamic Temperature ◽  
Fundamental Constants ◽  
Primary Thermometry ◽  
A Value ◽  
System Of Units ◽  
Mise En Pratique ◽  
Explicit Constant ◽  
Definition Of ◽  
Base Units

In 2018, it is expected that there will be a major revision of the International System of Units (SI) which will result in all of the seven base units being defined by fixing the values of certain atomic or fundamental constants. As part of this revision, the kelvin, unit of thermodynamic temperature, will be redefined by assigning a value to the Boltzmann constant k . This explicit-constant definition will define the kelvin in terms of the SI derived unit of energy, the joule. It is sufficiently wide to encompass any form of thermometry. The planned redefinition has motivated the creation of an extended mise en pratique (‘practical realization’) of the definition of the kelvin ( MeP -K), which describes how the new definition can be put into practice. The MeP -K incorporates both of the defined International Temperature Scales (ITS-90 and PLTS-2000) in current use and approved primary-thermometry methods for determining thermodynamic temperature values. The MeP -K is a guide that provides or makes reference to the information needed to perform measurements of temperature in accord with the SI at the highest level. In this article, the background and the content of the extended second version of the MeP -K are presented.

scholarly journals Definition of the mole (IUPAC Recommendation 2017)

2018 ◽  
Vol 90 (1) ◽  
pp. 175-180 ◽  
Author(s):  
Roberto Marquardt ◽  
Juris Meija ◽  
Zoltán Mester ◽  
Marcy Towns ◽  
Ron Weir ◽  
...  
Keyword(s):  
International System ◽  
International Committee ◽  
Fundamental Physical Constants ◽  
Weights And Measures ◽  
Technical Report ◽  
System Of Units ◽  
Iupac Recommendation ◽  
Definition Of ◽  
Base Units ◽  
Fundamental Physical

AbstractIn 2011 the General Conference on Weights and Measures (CGPM) noted the intention of the International Committee for Weights and Measures (CIPM) to revise the entire International System of Units (SI) by linking all seven base units to seven fundamental physical constants. Of particular interest to chemists, new definitions for the kilogram and the mole have been proposed. A recent IUPAC Technical Report discussed these new definitions in relation to immediate consequences for the chemical community. This IUPAC Recommendation on the preferred definition of the mole follows from this Technical Report. It supports a definition of the mole based on a specified number of elementary entities, in contrast to the present 1971 definition.

scholarly journals Mise en pratiquefor the definition of the candela and associated derived units for photometric and radiometric quantities in the International System of Units (SI)

Metrologia ◽  
2016 ◽  
Vol 53 (3) ◽  
pp. G1-G1 ◽  
Author(s):  
Joanne Zwinkels ◽  
Armin Sperling ◽  
Teresa Goodman ◽  
Joaquin Campos Acosta ◽  
Yoshi Ohno ◽  
...  
Keyword(s):  
International System ◽  
International System Of Units ◽  
System Of Units ◽  
Definition Of

scholarly journals When should we change the definition of the second?

2011 ◽  
Vol 369 (1953) ◽  
pp. 4109-4130 ◽  
Author(s):  
Patrick Gill
Keyword(s):  
Laser Cooling ◽  
Optical Lattice ◽  
Cold Atoms ◽  
International System ◽  
Atomic Clock ◽  
Optical Clock ◽  
Lattice Systems ◽  
System Of Units ◽  
Primary Standards ◽  
Definition Of

The microwave caesium (Cs) atomic clock has formed an enduring basis for the second in the International System of Units (SI) over the last few decades. The advent of laser cooling has underpinned the development of cold Cs fountain clocks, which now achieve frequency uncertainties of approximately 5×10 −16 . Since 2000, optical atomic clock research has quickened considerably, and now challenges Cs fountain clock performance. This has been suitably shown by recent results for the aluminium Al + quantum logic clock, where a fractional frequency inaccuracy below 10 −17 has been reported. A number of optical clock systems now achieve or exceed the performance of the Cs fountain primary standards used to realize the SI second, raising the issues of whether, how and when to redefine it. Optical clocks comprise frequency-stabilized lasers probing very weak absorptions either in a single cold ion confined in an electromagnetic trap or in an ensemble of cold atoms trapped within an optical lattice. In both cases, different species are under consideration as possible redefinition candidates. In this paper, I consider options for redefinition, contrast the performance of various trapped ion and optical lattice systems, and point to potential limiting environmental factors, such as magnetic, electric and light fields, collisions and gravity, together with the challenge of making remote comparisons of optical frequencies between standards laboratories worldwide.

scholarly journals Progress on vacuum-to-air mass calibration system using magnetic suspension to disseminate the Planck-constant realized kilogram

ACTA IMEKO ◽  
2017 ◽  
Vol 6 (2) ◽  
pp. 70 ◽  
Author(s):  
Eric Carl Benck ◽  
Corey Stambaugh ◽  
Edward Mulhern ◽  
Patrick Abbott ◽  
Zeina Kubarych
Keyword(s):  
International System ◽  
High Accuracy ◽  
Magnetic Suspension ◽  
Calibration System ◽  
Font Size ◽  
Planck Constant ◽  
Air Mass ◽  
System Of Units ◽  
Mass Calibration ◽  
Definition Of

<p><span style="font-size: small;">The kilogram is the unit of mass in the International System of units (SI) and has been defined as the mass of the International Prototype Kilogram (IPK) since 1889.  </span><span style="font-size: small;">In the future, a new definition of the kilogram will be realized by fixing the value of the Planck constant.</span><span style="font-size: small;">  </span><span style="font-size: small;">The new definition of the unit of mass will occur in a vacuum environment by necessity, so the National Institute of Standards and Technology (NIST) is developing a mass calibration system in which a kilogram artefact in air can be directly compared with a kilogram realized in a vacuum environment.</span><span style="font-size: small;">  </span><span style="font-size: small;">This apparatus uses magnetic suspension to couple the kilogram in air to a high accuracy mass balance in vacuum.</span><span style="font-size: small;"> </span></p><p> </p>

scholarly journals System of astronomical constants in the relativistic framework

1986 ◽  
Vol 114 ◽  
pp. 187-188
Author(s):  
T. Fukushima ◽  
M. K. Fujimoto ◽  
H. Kinoshita ◽  
S. Aoki
Keyword(s):  
Light Propagation ◽  
International System ◽  
Propagation Time ◽  
Long Baseline ◽  
System Of Units ◽  
Numerical Transformation ◽  
Unit Of Length ◽  
Range Rate ◽  
Definition Of ◽  
Astronomical Constants

The relation between the units and the readings of time and space coordinates of the terrestrial and the barycentric frames is discussed from the viewpoint of general relativity. Attention is paid to the unit of space coordinates since the International Astronomical Union (IAU) regulates only the unit of time coordinate in the above two frames. Two definitions on unit of length are examined and their effects on the numerical expression of coordinate transformation, equations of planetary motions, and those for light propagation time are discussed. A clear conflict is found between the IAU(1976) recommendation on the definition of the time-scales in different frames and the statement that all constants in the IAU(1976) new system of astronomical constants are defined in terms of the international system of units (SI units). In order to dissolve this conflict, one of the two examined definitions on unit of length is proposed to be adopted, which requests the least alteration on the current procedures to analyze the astrometric observations such as radar/laser rangings, range and range-rate measurements, and very long baseline interferometric observations. An interpretation of numerical values in the IAU(1976) system of astronomical constants is also presented. It is stressed that the definition proposed in this paper requires that a slightly different formula from the current one be used in the numerical transformation of coordinates between the terrestrial and the barycentric frames.

scholarly journals Thermodynamic properties of seawater, ice and humid air: TEOS-10, before and beyond

Ocean Science ◽  
2018 ◽  
Vol 14 (3) ◽  
pp. 471-502 ◽  
Author(s):  
Rainer Feistel
Keyword(s):  
Thermodynamic Properties ◽  
Hydrological Cycle ◽  
International System ◽  
Metrological Traceability ◽  
Humid Air ◽  
Ongoing Research ◽  
Seawater Salinity ◽  
System Of Units ◽  
Volume Energy ◽  
Definition Of

Abstract. In the terrestrial climate system, water is a key player in the form of its different ambient phases of ice, liquid and vapour, admixed with sea salt in the ocean and with dry air in the atmosphere. For proper balances of climatic energy and entropy fluxes in models and observations, a highly accurate, consistent and comprehensive thermodynamic standard framework is requisite in geophysics and climate research. The new Thermodynamic Equation of Seawater – 2010 (TEOS-10) constitutes such a standard for properties of water in its various manifestations in the hydrological cycle. TEOS-10 was recommended internationally in 2009 by the Intergovernmental Oceanographic Commission (IOC) to replace the previous 1980 seawater standard, EOS-80, and in 2011 by the International Union of Geodesy and Geophysics (IUGG) as the official description for the properties of seawater, of ice and of humid air. This paper briefly reviews the development of TEOS-10, its novel axiomatic properties, the new oceanographic tools it offers and the important tasks that still await solutions by ongoing research. Among the latter are new definitions and measurement standards for seawater salinity and pH in order to establish their metrological traceability to the International System of Units (SI) for the first time after a century of widespread use. Of similar climatological relevance is the development and recommendation of a uniform standard definition of atmospheric relative humidity that is unambiguous and rigorously based on physical principles.The leading thermodynamic properties of a fluid are determined by the relations which exist between volume, pressure, temperature, energy, and entropy … But all the relations existing between these five quantities for any substance …may be deduced from the single relation existing for that substance between volume, energy, and entropy. Josiah Willard Gibbs, 1873b

scholarly journals Watt Balance

2020 ◽  
Vol 1 (4) ◽  
Author(s):  
Ζωή Κουρουτζίδου ◽  
Άγγελος Θεολόγου ◽  
Βαγγέλης Μ Mαδεμλής ◽  
Νίκος Θρήσκος ◽  
Ευγένιος Μέττας ◽  
...  
Keyword(s):  
International System ◽  
International System Of Units ◽  
System Of Units ◽  
Watt Balance

To 1960 στο συνέδριο Μέτρων και Σταθμών έγινε πρόταση όλες οι χώρες να χρησιμοποιούν το ίδιο σύστημα μονάδων και έτσι δημιουργήθηκε το Διεθνές Σύστημα Μονάδων S.I ( International System of Units). Το μέτρο (m) είναι μια από τις θεμελιώδεις μονάδες του S.I και αρχικά ορίστηκε ως η απόσταση στους 0ο C μεταξύ δύο χαραγών πάνω σε μια ράβδο από ιριδιούχο λευκόχρυσο, που φυλάσσεται στο Διεθνές Γραφείο Μέτρων και Σταθμών στο Παρίσι. Αντίγραφα αυτού του προτύπου στάλθηκαν σε διάφορες χώρες. Δυστυχώς όμως τα μεταλλικά πρότυπα αλλοιώνονται με την πάροδο του χρόνου με αποτέλεσμα το μήκος τους να υφίσταται μικρές μεταβολές , που είναι όμως σημαντικές για τις μετρήσεις της σύγχρονης επιστήμης. Έτσι το 1983 το μέτρο ορίστηκε ξανά ως η απόσταση που διανύει το φως στο κενό σε χρόνο . Με δεδομένο ότι η ταχύτητα του φωτός είναι ακριβώς 299.792.458 m/s και αποτελεί μια φυσική σταθερά και η μονάδα μήκους (m) έχει καθοριστεί πλήρως. Παρόμοιο πρόβλημα είχαμε και με τη μονάδα μάζας (kg). Το 2011 έγινε μια προσπάθεια να καθοριστεί το (kg) με τη βοήθεια της σταθεράς του Planck h = 6,6260693x10^(-34) J.s. Η μέθοδος που χρησιμοποιήθηκε για τον καθορισμό του χιλιόγραμμου ,ονομάζεται Watt Balance ή Kibble Balance προς τιμή του εφευρέτη της Bryan Kibble. Στην παρούσα εργασία έγινε μια προσπάθεια μέτρησης της μάζας με τις αρχές της μεθόδου Kibble Balance.

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