OOIR: Observatory of International Research

Papers

(The median citation count of Metrologia is 1. The table below lists those papers that are above that threshold based on CrossRef citation counts [max. 250 papers]. The publications cover those that have been published in the past four years, i.e., from 2020-11-01 to 2024-11-01.)

Article	Citations
Optical frequency ratio of a ¹⁷¹Yb⁺ single-ion clock and a ⁸⁷Sr lattice clock	31
Demonstration of the nearly continuous operation of an¹⁷¹Yb optical lattice clock for half a year	29
Absolute frequency measurement of the ¹⁷¹Yb optical lattice clock at KRISS using TAI for over a year	24
The new mise en pratique for the metre—a review of approaches for the practical realization of traceable length metrology from 10⁻¹¹ m to 10¹³ m	23
Beginning of a new phase of the dissemination of the kilogram	20
A ⁸⁷Sr optical lattice clock with 2.9 × 10⁻¹⁷ uncertainty and its absolute frequency measurement	20
Roadmap towards the redefinition of the second	19
Review of field characterization techniques for high intensity therapeutic ultrasound	19
Absolute frequency of ⁸⁷Sr at 1.8 × 10⁻¹⁶ uncertainty by reference to remote primary frequency standards	19
Reduction of calibration uncertainty due to mounting of three-axis accelerometers using the intrinsic properties model	17
High-performance coherent population trapping atomic clock with direct-modulation distributed Bragg reflector laser	16
Refractive index gas thermometry between 13.8 K and 161.4 K	15
Thermodynamic effects in a gas modulated Invar-based dual Fabry–Pérot cavity refractometer	14
Measurement configurations for differential sampling of AC waveforms based on a programmable Josephson voltage standard: effects of sampler bandwidth on the measurements	14
Empirical decomposition and error propagation of medium-term instabilities in half-life determinations	13
The international reference system for pure beta-particle emitting radionuclides: an evaluation of the measurement uncertainties	13
First uncertainty evaluation of the cesium fountain primary frequency standard NMIJ-F2	13
Guidance on Bayesian uncertainty evaluation for a class of GUM measurement models	12
Absolute energies and emission line shapes of the L x-ray transitions of lanthanide metals	12
Primary calibration system for digital accelerometers	11
Continuous IPPP links for UTC	11
Ytterbium optical lattice clock with instability of order 10⁻¹⁸	11
Establishing waveguide lines as primary standards for scattering parameter measurements at submillimetre wavelengths	11
Preliminary study of generating a local time scale with NIM ⁸⁷Sr optical lattice clock	10
Refining the cold atom pressure standard	10

An AC quantum voltmeter for frequencies up to 100 kHz using sub-sampling	10
Improved frequency ratio measurement with ⁸⁷Sr and ¹⁷¹Yb optical lattice clocks at NMIJ	10
Final report on the CCM key comparison of kilogram realizations CCM.M-K8.2021	10
A critical review of the common thermocouple reference functions	10
Towards a consensus on a continuous coordinated universal time	9
The irony of the magnet system for Kibble balances—a review	9
Prenormative verification and validation of a protocol for measuring magnetite–maghemite ratios in magnetic nanoparticles	9
CCQM-K68.2019, nitrous oxide (N₂O) in air, ambient level, final report	9
Transient heating in fixed length optical cavities for use as temperature and pressure standards	9
On the influence of inlet perturbations on slug dynamics in horizontal multiphase flow—a computational study	9
Precise density measurement and its uncertainty evaluation for refractory liquid metals over 3000 K using electrostatic levitation	9
Precision measurement of an electron pump at 2 GHz; the frontier of small DC current metrology	8
A three-cornered hat analysis of instabilities in two-way and GPS carrier phase time transfer systems	8
Measurement of the ²⁷Al⁺ and ⁸⁷Sr absolute optical frequencies	8
Highly-accurate second-virial-coefficient values for helium from 3.7 K to 273 K determined by dielectric-constant gas thermometry	8
Thickness and refractive index measurements of a thin-film using an artificial neural network algorithm	8
A fully digital bridge towards the realization of the farad from the quantum Hall effect	8
Robustness tests for an optical time scale	8
Determination of the responsivity of a predictable quantum efficient detector over a wide spectral range based on a 3D model of charge carrier recombination losses	8
Towards traceable dynamic pressure calibration using a shock tube with an optical probe for accurate phase determination	8
Achieving traceability to UTC through GNSS measurements	8
A new calibration setup for lock-in amplifiers in the low frequency range and its validation in a bilateral comparison	8
Precise sinusoidal signal extraction from noisy waveform in vibration calibration	8
Quantification of titanium dioxide (TiO₂) anatase and rutile polymorphs in binary mixtures by Raman spectroscopy: an interlaboratory comparison	8
Acoustic measurement of the triple point of neon T _Ne and thermodynamic calibration of a transfer standard for accurate cryogenic thermometry	8
Thickness measurements and uncertainty evaluation of a multilayer thin-film sample using auxiliary single-layer samples	7
The comparability of the determination of the molar mass of silicon highly enriched in ²⁸Si: results of the CCQM-P160 interlaboratory comparison and additional external measurements	7
Two-point diameter calibration of a sphere using a micro-coordinate measuring machine at NMIJ	7
Gonioreflectometer for measuring 3D spectral BRDF of horizontally aligned samples with traceability to SI	7
Survey of subrange inconsistency of long-stem standard platinum resistance thermometers	7
Evaluation of the transportable atom gravimeter HUST-QG	7
A laser pistonphone designed for absolute calibration of infrasound sensors from 10 mHz up to 20 Hz	7
Role of measurement uncertainty in the comparison of average areal rainfall methods	7
Calibration of GNSS stations for UTC	7
Absolute frequency measurement of the ⁸⁷Sr optical lattice clock at NTSC using international atomic time	7
First realisation of the kilogram with the METAS Kibble balance	7
A metrological approach to quantities that are counted and the unit one	7
Realization and evaluation of the triple point of sulfur hexafluoride	7
Uncertainty evaluations from small datasets	7
PTB–INRIM comparison of novel digital impedance bridges with graphene impedance quantum standards	6
Evaluation of blackbody radiation shift with 2 × 10⁻¹⁸ uncertainty at room temperature for a transportable ⁴⁰Ca⁺ optical clock	6
Measurements of absolute, SI-traceable lunar irradiance with the airborne lunar spectral irradiance (air-LUSI) instrument	6
Rejection sampling for Bayesian uncertainty evaluation using the Monte Carlo techniques of GUM-S1	6
Metrological approach of γ-emitting radionuclides identification at low statistics: application of sparse spectral unmixing to scintillation detectors	6
Method to traceably determine the refractive index by measuring the angle of minimum deviation	6
SI-traceable solar irradiance measurements for aerosol optical depth retrieval	6
On the uncertainties in the realization of the kelvin based on thermodynamic temperatures of high-temperature fixed-point cells	6
Primary standard for the number concentration of liquid-borne particles: extension of the diameter range from the micrometer to the sub-micrometer level and reduction of the measurement uncertainty	6
Final report on the CIPM key comparison CCAUV.V-K5	6
Revisiting the limits of photon momentum based optical power measurement method, employing the case of multi-reflected laser beam	6

Coherent fiber links operated for years: effect of missing data	6
Proposal for the dimensionally consistent treatment of angle and solid angle by the International System of Units (SI)	6
Finite element analysis of blackbody radiation environment for an ytterbium lattice clock operated at room temperature	5
Differential sampling of AC waveforms based on a programmable Josephson voltage standard using a high-precision sampler	5
Evaluation of effective area of air piston gauge with limitations in piston–cylinder dimension measurements	5
On the dimension of angles and their units	5
A bilateral comparison of NIST and PTB laser power standards for scale realization confidence by gravitational wave observatories	5
Axial force radiometer for primary standard laser power measurements using photon momentum	5
Traceability for nuclear medicine: the status of primary radioactivity standards	5
Defining relative humidity in terms of water activity: III. Relations to dew-point and frost-point temperatures	5
Primary thermometry at 4 K, 14 K, and 25 K applying dielectric-constant gas thermometry	5
Precise measurement of the thickness of silicon wafers by double-sided interferometer and bilateral comparison	5
Corrigendum: Realization of the triple point of carbon dioxide evaluated by the ITS–90 (2020 Metrologia 57 015004)	5
CCQM-K143 comparison of copper calibration solutions prepared by NMIs/DIs	5
Ode to Bayesian methods in metrology	5
ITS-90 reproducibility, xenon fixed point substitution and new interpolating equations between 13.8033 K and 273.16 K	5
Improved absolute frequency measurement of the strontium ion clock using a GPS link to the SI second	5
Final report on CCQM-K167: carbon isotope delta measurements of vanillin	5
Final report of the new BIPM comparison BIPM.RI(II)-K1.Ra-223 of activity measurements of the radionuclide ²²³Ra including the 2014 result of the NPL (United Kingdom), the 2014 result of th	5
Errors-in-variables calibration with dark uncertainty	5
Uncertainty budget for PTB’s gonioreflectometers and ways to improve it in the short VIS spectral range	5
On the long-term stability of the triple-point-of-water cells	5
A comparison of traceable spatial angle autocollimator calibrations performed by PTB and VTT MIKES	5
International comparison CCQM-K118 natural gas	5
High amplification laser-pressure optic enables ultra-low uncertainty measurements of optical laser power at kilowatt levels	5
Evaluation of different general V(λ) mismatch indices of photometers for LED-based light sources in general lighting applications	5
Detection and identification of faults in clock ensembles with the generalized likelihood ratio test	5
Angles in the SI: a detailed proposal for solving the problem	5
A further short history of the SI prefixes	5
Uncertainty analysis of stack gas flow measurements with an S-type Pitot tube for estimating greenhouse gas emissions using a continuous emission monitoring system	5
Experimental validation of theoretically predicted cut-off of L₁–L₃M_4,5 transitions at Z = 50 through measurements of fluorescence and Coster–Kronig yi	5
Correction factors for primary beta dosimetry	5
A strontium lattice clock with both stability and uncertainty below 5×10−18	5
Final report for supplementary comparison APMP.QM-S15: carbon dioxide in nitrogen at 1000 μmol/mol	4
Type A uncertainty analysis validation of type B analysis for three-axis accelerometer calibrations	4
Verification of an in situ calibrated optomechanical accelerometer for use as a strong ground motion seismic reference	4
The least informative distribution and correlation coefficient of measurement results	4
Final report for supplementary comparison APMP.QM-S9.2017: 100 μmol/mol of carbon monoxide in nitrogen	4
Remote time and frequency calibration with holdover traceability from a new treatment of non-white noise in rubidium clocks	4
The value of stable, comparable and standardised measurement: enabling confidence in decision making for societal challenges	4
Interlaboratory consensus building	4
Speedy in-situ magnetic field compensation algorithm for multiple-channel single-beam SERF atomic magnetometers	4
UME Kibble balance operating in air	4
Improvements of the programmable quantum current generator for better traceability of electrical current measurements	4
Direct comparison of ITS-90 and PLTS-2000 from 0.65 K to 1 K at LNE-CNAM	4
Gas flow standards and their uncertainty	4
Mass fraction assignment of Bisphenol-A high purity material	4
A method for calibrating forward scatter meters indoors	4
The CCRI(II)-K2.Fe-55.2019 key comparison of activity concentration measurements of a ⁵⁵Fe solution	4
Report of the CCQM-K152. Assay of potassium iodate	4
Ambient humidity, the overlooked influencer of radioactivity measurements	4
International comparison CCQM-K10.2018: BTEX in nitrogen at 5 nmol mol⁻¹	4
Thickness measurement of nm HfO₂ films	4
Terahertz frequency counter based on a semiconductor-superlattice harmonic mixer with four-octave measurable bandwidth and 16-digit precision	4
PAWG Pilot Study on Quantification of SARS-CoV-2 Monoclonal Antibody - Part 1	4
ITS-90 SPRT calibration from the Ar TP to the Zn FP	4
International comparison CCQM-K117 ammonia	4
Comment on ‘Angles in the SI: a detailed proposal for solving the problem’	4
Development of a new KRISS low frost-point generator with improved uncertainty from 7 nmol·mol⁻¹ to 1000 nmol·mol⁻¹	3
Long-term spectral responsivity stability of predictable quantum efficient detectors	3
The kilogram: inertial or gravitational mass?	3
International comparison of activity measurements of radon 222 - EURAMET Project n°1475 - EURAMET.RI(II)-S8.Rn-222	3
A high precision VIS/NIR dynamic goniometer-spectrometer	3
International comparison CCQM-K74.2018: Nitrogen dioxide, 10 μmol mol-1	3
Measurement of miscut angles in the determination of Si lattice parameters	3
Development of a primary measurement standard for trace moisture in Ar	3
Precise high resistance comparison between the NMIJ traveling dual source bridge and the NIST adapted Wheatstone bridge	3
Supplementary comparison EURAMET.EM-S42, comparison of lightning impulse (LI) reference measuring systems	3
Activity measurements of the radionuclides ^99mTc, ¹⁸F and ⁶⁴Cu for the POLATOM, Poland, in the ongoing comparisons BIPM.RI(II)-K4 series and KCRV update in the corres	3
International comparison CCQM-K165: dimethyl sulfide in nitrogen at 5 nmol mol^-1	3
Reply to Comment on ‘Angles in the SI: a detailed proposal for solving the problem’	3
Simple informative prior distributions for Type A uncertainty evaluation in metrology	3
Increased detector response in optical overfilled measurements due to gas lens formation by nitrogen flow through the entrance aperture	3
Residual resistance ratio as indicator for the influence of impurities on fixed-point temperatures	3
Final report of CCQM-P204, comparison on CO₂ isotope ratios in pure CO₂	3
Development and implementation of an automated four-terminal-pair Josephson impedance bridge	3
Candidate primary reference measurement procedure for the amount-of-substance content of a complexing agent expressed as EDTA based on the coulometric titration with electrogenerated Hg ions	3
Economic optimization of acceptance interval in conformity assessment: 1. Process with no systematic effect	3
A constant pressure flowmeter for extreme-high vacuum	3
Enhanced dilution step and gravimetric preparation uncertainty for low-amount fraction standard gas mixtures using a newly developed automatic weighing system for a mini cylinder	3

Assay of sodium carbonate	3
Key Comparison Study - Organic Solvent Calibration Solution - Gravimetric preparation and value assignment of aflatoxin B1 (AfB1) in acetonitrile (ACN)	3
Effects of fast x-ray cone-beam tomographic measurement on dimensional metrology	3
Traceable spectral interferometry for length measurement	3
Accurate ground-to-ground laser time transfer by diffuse reflections from tumbling space debris objects	3
Final report of the new BIPM comparison BIPM.RI(II)-K1.Ac-225 of activity measurements of the radionuclide ²²⁵Ac to include the 2019 result of the PTB (Germany)	3
A digital framework for realising the SI—a proposal for the metre	3
A virtual flow meter downstream of various elbow configurations	3
Effects of rotation errors on goniometric measurements	3
Mid-infrared spectral responsivity scale based on an absolute cryogenic radiometer and a tunable quantum cascade laser	3
The CIPM list ‘Recommended values of standard frequencies’: 2021 update	3
Some predictions of a validated physical model of Pt–Rh thermocouple drift above 1200 °C	3
Economic optimization of acceptance interval in conformity assessment: 2. Process with unknown systematic effect	3
Scaling of thermoelectric inhomogeneities with temperature in platinum–rhodium alloyed thermocouples	3
Characterization of predictable quantum efficient detector in terms of optical non-linearity in the visible to near-infrared range	3
Evaluation of long-term robustness of the International System of Reference (SIR) used in radionuclide metrology based on the meta-analysis of its machine-readable database	3
Key comparison BIPM.RI(I)-K4 of the absorbed dose to water standards of the NIM, China and the BIPM in ⁶⁰Co gamma radiation	2
Calibration process and uncertainty estimation for 3D pitot tubes to enhance greenhouse gas emission measurements in smokestacks	2
Characteristics of a real-time ensemble time scale corrected by the KRISS-PSFS using a reduced Kalman filter (Kred) algorithm	2
A method for evaluating the force factor in oscillating Kibble balances with application to the Planck-Balance	2
CCQM-P206, nitrous oxide (N₂O) in air, ambient level, pilot study run in parallel with CCQM-K68.2019	2
Pilot study on peptide purity - glycated hexapeptide of HbA1c	2
On the distinction between SI base units and SI derived units	2
Decadal validation of the LASP TRF cryogenic radiometer by NIST, and establishment of a replacement room temperature standard*	2
Key comparison COOMET.QM-K120 "Carbon dioxide in air at urban level (480–800) μmol/mol"	2
Experimental investigation of pressure characteristics behind the reflected shock waves in a metrological shock tube	2
CCEM key comparison CCEM.RF-K26. Attenuation at 18 GHz, 26.5 GHz and 40 GHz using a step attenuator. Final report of the pilot laboratory	2
Uncertainty evaluation in reference material characterization by double isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS)	2
A novel high accuracy micrometer for the measurement of diameter	2
Key Comparison CCQM-K73.2018 Amount Content of H⁺ in Hydrochloric Acid (0.1 mol·kg⁻¹)	2
Evaluation of the blackbody radiation shift of an Yb optical lattice clock at KRISS	2
Final report on APMP.QM-K18.2016 key comparison on pH measurement of carbonate buffer	2
Calculation of magnetic forces and torques on the Kibble coil	2
Traceable methods for calibrating condensation particle counters at concentrations down to 1 cm⁻³	2
CCAUV.W-K2 final report - key comparison CCAUV.W-K2: calibration of hydrophones in the frequency range from 250 Hz to 500 kHz	2
Update of the BIPM comparison BIPM.RI(II)-K1.Ac-225 of activity measurements of the radionuclide ²²⁵Ac to include the 2021 result of the POLATOM (Poland)	2
Key comparison BIPM.RI(I)-K1 of the air-kerma standards of the GUM, Poland and the BIPM in ⁶⁰Co gamma radiation	2
Key comparison BIPM.RI(I)-K2 of the air-kerma standards of the KRISS, Republic of Korea, and the BIPM in low-energy x-rays	2
Characterization of the LED filament lamp for luminous intensity calibration	2
Final report, ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with DMDM, September 2022	2
Adoption of ICRU report 90 recommendations in the Canadian Co-60 air-kerma primary standard	2
The unusual status of the hectare in the SI	2
Efficient experimental sampling through low-rank matrix recovery	2
COOMET supplementary comparison on wavelength for fiber optics	2
International comparison CCQM-K41.2017, hydrogen sulfide in nitrogen	2
Advances in metrology for energy-containing gases and emerging demands	2
Primary standard for traceability in low liquid hydrocarbon fuel flow rates	2
Update of the BIPM comparison BIPM.RI(II)-K1.Gd-153 of activity measurements of the radionuclide ¹⁵³Gd to include the 2020 result of the NIST (United States)	2
New metrological capabilities for measurements of dynamic liquid flows	2
Comparison of four-terminal-pair 1 pF, 10 pF, 100 pF and 1000 pF capacitance standards at frequencies of 10 kHz, 100 kHz, 1 MHz and 10 MHz (APMP.EM-S15)	2
Key comparison BIPM.RI(I)-K4 of the absorbed dose to water standards of the GUM, Poland and the BIPM in ⁶⁰Co gamma radiation	2
Determination of absolute Np L x-ray emission intensities from ²⁴¹Am decay using a metallic magnetic calorimeter	2
NRC measurement set-up and preparatory work for CCT-K7.2021 key comparison of triple-point-of-water cells	2
Automatic alignment technique for the suspended coil in the joule balance	2
Calibration of a precision current measurement system for high AC voltages using an AC quantum voltmeter	2
Comparison in dynamic primary calibration of digital-output accelerometer between CEM and PTB	2
PAWG pilot study on quantification of SARS-CoV-2 monoclonal antibody - Part 2	2
Research on a time scale algorithm based on multi-dimensional weighted average	2
Temperature dependence correction method of LED filament lamp for total luminous flux calibration based on voltage measurement	2
Supplementary comparison of the measurement of the alpha and beta particle surface emission rates from large area sources (CCRI(II)-S10 LASCE)	2
Precise underwater distance measurement using laser frequency comb	2
A dynamic gravimetric standard for liquid flow measurements	2
Final report "Key comparison CCM.FF-K1.2015 - water flow: 30 m³/h ... 200 m³/h"	2
The CIPM MRA—success and performance	2
Understanding immersion in zinc fixed-point cells using factorial design of experiments	2
International comparison CCQM-K3.2019 automotive exhaust gases	2
Final report of the new BIPM comparison BIPM.RI(II)-K1.Tb-161 of activity measurements of the radionuclide ¹⁶¹Tb including the 2019 result of the IRA (Switzerland)	2
EURAMET.EM-S44 comparison for ultra-low DC current sources	2
Final report on the CCPR Key Comparison CCPR-K3.2014 Luminous Intensity	2
Facility for calibrating anemometers as a function of air velocity vector and turbulence	2
Series connection of quantum Hall resistance array and programmable Josephson voltage standard for current generation at one microampere	2
Update of the BIPM comparison BIPM.RI(II)-K1.Sr-85 of activity measurements of the radionuclide ⁸⁵Sr to include the 2018 result of the PTB (Germany)	2
Primary calibration for airborne infrasound utilizing the vertical gradient of the ambient pressure	2
Final report of CCQM-K172 on measurement of Specific Adsorption A [mol/kg] of Ar on zeolite at liquid argon temperature (to enable a traceable determination of the Specific Surface Area by following I	2
Internal quantum efficiency of silicon photodetectors at ultraviolet wavelengths	2
Absolute frequency measurement of a Yb optical clock at the limit of the Cs fountain	2
Realization of the triple point of carbon dioxide in a transportable cell using long-stem SPRTs	2
Comment on ‘On the dimension of angles and their units’	2
Investigation of the uncertainty contributions of the alignment of PTB’s double-ended interferometer by virtual experiments	2
Uncertainty in the mutual calibration method for the traceable thickness measurement of ultra-thin oxide films	2
Newtonian gravitational constant measurement. All atomic variables become extreme when using a source mass consisting of three or more parts	2
Update of the BIPM comparison BIPM.RI(II)-K1.Co-60 of activity measurements of the radionuclide ⁶⁰Co to include the 2020 result of the PTB (Germany), the 2020 result of the NIST (United Sta	2
Extension of NIM illuminance scale to very low levels (1 × 10⁻¹⁰ lx to 2 lx)	2
Determination of sensitivity coefficients and their uncertainties in Rockwell hardness measurement: a Monte Carlo method for multiple linear regression	2
Key comparison BIPM.RI(I)-K3 of the air-kerma standards of the KRISS, Republic of Korea, and the BIPM in medium-energy x-rays	2
Novel developments of refractive power measurement techniques in the automotive world	2
Achievement of 0.005% combined transfer uncertainties in the NIST detector calibration facility	2
Femtosecond-comb based 10 MHz-to-optical frequency link with uncertainty at the 10⁻¹⁸ level	2
Phase shifting angle interferometer	2
Supplementary comparison for the traceability of AC high voltage reference measuring systems up to 200 kV (EURAMET.EM-S33)	1
Key comparison BIPM.RI(I)-K7 of the air-kerma standards of the NMIJ, Japan and the BIPM in mammography x-rays	1
Bilateral comparison of irradiance scales between PMOD/WRC and PTB for longwave downward radiation measurements	1
Use of bidirectional transmittance distribution function measurements to determine transmittance haze	1
Editorial for the Metrologia Focus Issue on Length Metrology	1
Bilateral comparison of 10 V standards between the NSAI-NML (Ireland) and the BIPM	1