Implementing the new kelvin

Short Name: InK, Project Number: SIB01

Coordinator

Direct measurements of extreme temperatures: A new way to measure temperature

Temperature measurements are difficult above 1300 K, typically present in iron, steel, and glass manufacture, and at the low temperatures used in the cryogenics industry and for quantum information processing research. Research is needed to make the redefined SI kelvin based on fundamental properties accessible to all users.

The EMRP project Implementing the new kelvin (InK1) addressed some of the challenges associated with practically generating and measuring thermodynamic temperature, particularly at the extremes of the international temperature scales.

The project:

Constructed high temperature fixed points of precisely known melting points to enable reliable transfer of thermodynamic temperature to 2750 K.
Developed methods for realising and transferring traceable thermodynamic temperatures above 1300 K directly, without using temperature scales and is now recommending two approaches to the thermometry community for use.
Determined the difference between thermodynamic temperature values and ITS-90 using acoustic and dielectric constant methods and achieved the lowest levels of uncertainty to date between 25 K to ~303 K.
Determined the difference between thermodynamic temperature values and PLTS-2000 using three thermodynamic methods over the higher temperature part of its range (that means above 0.02 K to 1K). This in part provides the foundation for the future use of thermodynamic temperature in this range without reliance on a temperature scale.

This project has established new fixed points as reliable high temperature standards and demonstrated the feasibility of using thermodynamic temperature methods for direct temperature traceability independent of the ITS-90 temperature scale. Research will continue in the follow on EMPIR project InK2 to develop the facilities, thermometry methods and documentation that will need to be in place to support the redefinition of the kelvin. Work is ongoing for both extending the low uncertainties achieved in InK1 across the range of the ITS-90 and, in addition, down to the lowest point of PLTS-2000 (0.0009 K) and so understand and resolve the current discrepancy in data on which the PLTS-2000 is founded. These are the necessary first steps for the practical implementation of the kelvin using thermodynamic temperature with the long term aim of making direct traceability to the redefined kelvin available to a wide variety of users in industry, medicine, meteorology and scientific research without recourse to any defined scale.

EMPIR projects 15SIB02 INK 2 and 18SIB02 Real-K build on this work.

Links

Project website

Link

Final Report

Final Publishable Report Implementing the new kelvin (SIB01) 2.11 MB

Publishable Summary

Final Publishable Summary Implementing the new kelvin (SIB01) 0.31 MB

Publications

Accurate Coulomb Blockade Thermometry up to 60 Kelvin

2016

Philosophical Transactions of the Royal Society A

Towards implementing the new kelvin

2016

Philosophical Transactions A

Progress towards the determination of thermodynamic temperature with ultra-low uncertainty

2016

Philosophical Transactions of the Royal Society A

A SQUID-based primary noise thermometer for low-temperature metrology

2016

Philos Trans A Math Phys Eng Sci

Dissemination of thermodynamic temperature above the freezing point of silver

2016

Philosophical Transactions of the Royal Society A

Estimates of the difference between thermodynamic temperature and the ITS-90 in the range 118 K to 303 K

2016

Philosophical Transactions of the Royal Society A

Thermodynamic temperature assignment to the point of inflection of the melting curve of high-temperature fixed points

2016

Philosophical Transactions of the Royal Society A

A comparison of irradiance responsivity and thermodynamic temperature measurement between PTB and NIM

2016

AIP Conference Proceedings

Linking the thermodynamic temperature to an optical frequency: recent advances in Doppler broadening thermometry

2016

Philosophical Transactions A

Acoustic and microwave tests in a cylindrical cavity for acoustic gas thermometry at high temperature

2016

Philosphical Transactions of the Royal Society A

Primary current-sensing noise thermometry in the millikelvin regime

2016

Philosophical Transactions of the Royal Society A

Thermodynamic temperature by primary radiometry

2016

Philosophical Transactions of the Royal Society A

The kelvin redefinition and its mise en pratique

2016

Phiolosophical Transactions of the Royal Society A

The Boltzmann constant from the H2 O18 vibration–rotation spectrum: complementary tests and revised uncertainty budget

2015

Metrologia

Characterization of the frequency stability of an optical frequency standard at 1.39 µm based upon noise-immune cavity-enhanced optical heterodyne molecular spectroscopy

2015

Optics Express

Experimental assessment of methods of dissemination of the thermodynamic temperature at the highest temperatures

2015

International Congress of Metrology

Investigating the ultimate accuracy of Doppler Broadening Thermometry by means of a global fitting procedure

2015

Physical Review A

A determination of the molar gas constant R by acoustic thermometry in helium

2015

Metrologia

Correlations among acoustic measurements of the Boltzmann constant

2015

Metrologia

Evaluation and Selection of High-Temperature Fixed-Point Cells for Thermodynamic Temperature Assignment

2015

Int J Thermophys

Determination of the Boltzmann constant k from the speed of sound in helium gas at the triple point of water

2015

Metrologia

Measurement of pressures up to 7 MPa applying pressure balances for dielectric-constant gas thermometry

2015

Metrologia

Improved radiation thermometry measurement uncertainty through implementing a primary scale in an industrial laboratory

2015

International Congress of Metrology

Alternative Methods of Blackbody Thermodynamic Temperature Measurement Above Silver Point

2015

International Journal of Thermophysics

Comparison of extrapolated and interpolated temperature scales from 1000 C to 2500 C between a national measurement institute and an ISO17025 accredited calibration laboratory

2015

Measurement

Progress towards an acoustic determination of the Boltzmann constant at CEM-UVa

2015

Metrologia

Improved electronic measurement of the Boltzmann constant by Johnson noise Thermometry

2015

Metrologia

Tunnel-Junction Thermometry Down to Millikelvin Temperatures

2015

APS Physics

Improving acoustic determinations of the Boltzmann constant with mass spectrometer measurements of the molar mass of argon

2015

Metrologia

A calculable and correlation-based magnetic field fluctuation thermometer

2014

Journal of Physics

Proposed Process for Estimating Definitive Temperatures of High-Temperature Fixed Points

2014

Int J Thermophys

the Euramet metrology research programme project: Implementing the new kelvin (ink)

2014

Int. J. Thermophysic, 2014

Line-narrowing effects in the near-infrared spectrum of water and precision determination of spectroscopic parameters

2014

J . Chem. Phys

Acoustic gas thermometry

2014

Metrologia

The Boltzmann constant from the shape of a molecular spectral line

2014

Journal of Molecular Spectroscopy

Thermodynamic Temperatures of High-Temperature Fixed Points: Uncertainties Due to Temperature Drop and Emissivity

2014

Int J Thermophys

Absolute frequency stabilization of an extended-cavity diode laser by means of noise-immune cavity-enhanced optical heterodyne molecular spectroscopy

2014

Optics Letters

Microwave Dimensional Measurements of Cylindrical Resonators for Primary Acoustic Thermometry

2014

International Journal of Thermophysics

Current Sensing Noise Thermometry: A Fast Practical Solution to Low Temperature Measurement

2014

Journal of Low Temperature Physics

Design and test of gas tight microwave transmission lines for resonance frequency measurements with cavity resonators up to 830 K

2014

CPEM

Experimental test of the quadratic approximation in the partially-Correlated Speed-Dependent Hard-Collision profile

2014

Physical Review A

Comparison of Co-C eutectic fixed-point cells between VNIIM and VNIIOFI

2013

AIP Conference Proceedings

Development of a new radiometer for the thermodynamic measurement of high temperature fixed points

2013

AIP Conference Proceedings

Lens transmission measurement for an absolute radiation thermometer

2013

AIP Conference Proceedings

Reducing uncertainty in practical radiation thermometer calibration based on proposed changes to the mise en pratique of the definition of the kelvin

2013

International Congress of Metrology

Measurement of thermodynamic temperature of high temperature fixed points

2013

AIP Conference Proceedings

Thermodynamic temperature measurements of silver freezing point and HTFPs

2013

AIP Conference Proceedings

COMPARATIVE INVESTIGATIONS OF COBALT–CARBON EUTECTIC HIGH-TEMPERATURE FIXED POINT CELLS CONSTRUCTED AT THE VNIIM AND VNIIOFI

2013

Measurement Techniques

Measurement of the thermodynamic temperature of high-temperature fixed points

2013

Measurement Techniques

Assigning Thermodynamic Temperatures To High-Temperature Fixed-Points

2013

AIP Conference Proceedings

A microkelvin cryogen-free experimental platform with integrated noise thermometry

2013

New Journal of Physics

Determination of the Boltzmann Constant by Means of Precision Measurements of H218O Line Shapes at 1.39 μm

2013

Physical Review Letters

Calibration of the Irradiance Responsivity of a Filter Radiometer for T Measurement at NIM

2011

International Journal of Thermophysics

Spectral Radiation Drift of LEDs Under Step-Mode Operation and Its Effect on the Measurement of the Non-Linearity of Radiation Thermometers

2011

International Journal of Thermophysics

Nonlinearity measurement of filter radiometers using water-cooled LED radiation sources

2011

Proceedings of NEWRAD 2011

Information