Metrologia

Article	Citations
Key comparison CCQM-K179 - polar analyte in solid organic material: mass fraction of oxytetracycline hydrochloride salt	135
SIM supplementary comparison on calibration of conventional mass of a 20 kg weight	48
Final report of the supplementary comparison between NIMT and LNE on pressure standards in the range 50 MPa to 500 MPa of hydraulic gauge pressure	46
Report of the CCRI(II) supplementary international comparison of measurement of activity per unit mass of Cs-134 and Cs-137 in wheat flour (CCRI(II)-S13)	33
Final report on the EURAMET key comparison EURAMET AUV.V-K5	26
SIM Thermocouple Type S Supplementary Comparison	23
Key comparison of voltage unit standards based on the Josephson effect	22
Comparison of calibration of multimeter	22
Measurement of melting and freezing temperature of iron using radiation thermometry	21
Update of the BIPM comparison BIPM.RI(II)-K1.Ga-67 of activity measurements of the radionuclide 67Ga to include the 2023 result of the CMI (Czechia)	21
Report on EURAMET supplementary comparison on measurement of a 1 mm stage micrometer	20
Reply to Comment on ‘The Avogadro constant is not the defining constant of the mole’	19
Final report, ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with EMPA, June 2023	19
Corrigendum: Detection and identification of faults in clock ensembles with the generalized likelihood ratio test (2022 Metrologia 59 045010)	18
Absolute frequency measurement of a Lu+ (3D1) optical frequency standard via link to international atomic time	18
Low-frequency calibration of accelerometers by rotation in the gravitational field at NIST	16
Bilateral Comparison of AC Programmable Josephson Voltage Standard (0.75 V rms and 7 V rms) between the PTB (Germany) and the BIPM, June 2025 (part of the ongoing BIPM key comparison BIPM.EM-K10.c a	16
Final report of CCQM-K96.2023: assay of potassium dichromate	15
Relating SI units to the ‘defining constants’	14
Key comparison BIPM.RI(I)-K2 of the air-kerma standards of the BFKH, Hungary, and the BIPM in low-energy x-rays	14
Final Report on key comparison EURAMET.M.P K4.2020 in the range from 1 Pa to 15 kPa of absolute and gauge pressure	14
Comparison of low air speed facilities	14
Final report of APMP.AUV.V-S1: supplementary comparison on calibration of laser tachometers using mechanical generators	14
Characterization of the LED filament lamp for luminous intensity calibration	13
CORRIGENDUM: Angles in the SI—a practical dimensional metrologist viewpoint * (2026 Metrologia  63 013	13

CIPM key comparison of viscosity CCM.V-K4	13
Comparison between four integer ambiguity resolved PPP GNSS time transfer software solutions	13
CCQM-K68.2019, nitrous oxide (N2O) in air, ambient level, final report	13
APMP key comparison of AC-DC current transfer standards: final report	13
Report on the APMP key comparison of hydrometer calibrations APMP.M.D-K4	12
Determining the calibration factor of Rn-220 by low-pressure scintillation cell	12
Discussion on the calculation of the uncertainties of [UTC-UTC(k)]	11
NTSC SrII optical lattice clock with uncertainty of 2	11
Key comparison BIPM.RI(I)-K7 of the air-kerma standards of the BFKH, Hungary, and the BIPM in mammography x-rays	11
International Comparison CCQM-K10.2018.1 - BTEX gas mixtures	11
Key comparison BIPM.RI(I)-K5 of the air-kerma standards of the GUM, Poland and the BIPM in 137Cs gamma radiation	11
Corrigendum: Uncertainty of the measurement of the frequency dependence of four-terminal pair capacitance with a four-channel vector network analyzer (2025 Metrologia	10
Comparison of blackbody for clinical infrared ear thermometers	10
Autocollimators: plane angle measurand ambiguities and the impact of surface form	10
CCM.G-K2.2023: CIPM key comparison of absolute gravimeters	10
Evaluations of the decay data of 40 K, 45 Ti, 56	10
High polarity analyte(s) in aqueous media: Determination of L-PFOA and L-PFOS in ground water	9
Series connection of quantum Hall resistance array and programmable Josephson voltage standard for current generation at one microampere	9
Final report on key comparison APMP.M.P-K7.2 in hydraulic gauge pressure from 10 MPa to 100 MPa	8
The forgotten (?) potentiometric method in thermometry	8
The unusual status of the hectare in the SI	8
Reply to Second Comment on ‘The Avogadro constant is not the defining constant of the mole’	8
Traceable characterisation of fibre-coupled single-photon detectors	8
Key comparison CCQM-K148.b - polar analyte in solid organic material: mass fraction of oxytetracycline	8
Gas viscosities from a semiconductor-manufacturing mass-flow controller	8
Final report for CCQM-P212: coherence of carbon isotope delta reference materials	8
Measurement model of circadian action factor of phosphor-converted white LEDs based on photometric, electrical, and thermal properties	7
A proposal for three categories of units within the SI	7
Total radiant flux measurement of UV LEDs using a gonio-spectroradiometer	7
Application of a bandwidth correction method to thin-film reflectance measurements	7
Machine learning based priors for Bayesian inversion in MR imaging	7
Applying heat transport modelling to reduce measurement uncertainty of the LASP reference standard NACR8 *	7
Phase shifting angle interferometer	7
Ambient humidity, the overlooked influencer of radioactivity measurements	7
Room temperature dual-mode internal quantum deficiency measurement with propagated uncertainty to 0.03% (k = 2)	6
Evaluations of the decay data of 57 Co, 76 Br, 133m	6
Bilateral comparison of 10 pF and 100 pF standards (ongoing BIPM key comparisons BIPM.EM-K14.a and 14.b) between the NMIM (Malaysia) and the BIPM	6
Linkage for Metrosert to CCT-K9 via the EURAMET-T.K9.1 bilateral comparison	6
Key comparison CCEM.RF-K27.W of RF power from 50 GHz to 75 GHz in rectangular waveguide	6
A simple tool for weighted averaging of inconsistent data sets	6
Multi-taper-based automatic correction of non-anechoic antenna measurements	6
Final report on the CCM key comparison of kilogram realizations CCM.M-K8.2021	6
Update of the BIPM comparison BIPM.RI(II)-K1.Co-57 of activity measurements of the radionuclide 57Co to include the 2023 result of the BEV (Austria)	6
Accurate characterisation of optical diffuse transmission—primary facility and extension to translucent samples	6
Method for traceable calibration of 5G NR measuring receivers	6
A new interpolation equation in the ITS-90 subrange from the triple point of water to the freezing point of indium	6
Evaluation of the transportable atom gravimeter HUST-QG	6
Pilot study CCQM-P172 – spectroscopic methods for HNO3 value assignment	5
Lunar reference timescale	5
Calibration of GNSS stations for UTC	5

Power of a test for assessing interlaboratory consensus of nominal and ordinal characteristics of a substance, material, or object	5
Continuous GPS PPP-AR frequency transfer links	5
Precise high resistance comparison between the NMIJ traveling dual source bridge and the NIST adapted Wheatstone bridge	5
Final report, ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with NIST, July 2022	5
Corrigendum: Accuracy evaluation of primary frequency standard NIST-F4 (2025 Metrologia  62 035002)	5
Precision measurement of an electron pump at 2 GHz; the frontier of small DC current metrology	5
Key comparison COOMET.QM-K120 "Carbon dioxide in air at urban level (480–800) μmol/mol"	5
Accurate density measurement of a small solid sample using a combination of hydrostatic weighing and pressure-of-flotation methods	5
Precision control of resistive power in Kibble balance coils: an advanced method for minimizing temperature-related magnetic errors	5
Erratum: Metrological characterization of a commercial single-photon source with high photon flux emission (2024 Metrologia 61 054001)	5
Final report of SIM supplementary comparison on testing machine calibration in compression up to 100 kN.	5
Measurement science meets the reproducibility challenge	5
First evaluation of the primary frequency standard NTSC-CsF2	5
Key comparison BIPM.RI(I)-K4 of the absorbed dose to water standards of the NMIJ, Japan, and the BIPM in 60Co gamma radiation	5
AFRIMETS.AUV.A-S2 final report, calibration of a multi-function acoustic calibrator	5
Final report, On-going Key Comparison BIPM.QM-K1, Ozone at ambient level, comparison with NIM Oct.2023	5
A proposal to change the leap-second adjustments to coordinated universal time	5
Comparison of PLTS-2000 and the magnetic field fluctuation thermometer at LNE-Cnam	5
Report of the comparison BIPM.QM-K2.b, on carbon dioxide in nitrogen at ambient levels, with E+ E Elektronik (2025)	4
Final report on the CCM key comparison of density measurements of a silicon sphere (1 kg) by hydrostatic weighing (CCM.D-K1.2023)	4
Bilateral comparison of 1.018 V and 10 V standards between CSIR-NPL (India) and the BIPM, April to June 2022 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)	4
Torque euramet supplementary comparison EURAMET.M.T-S4 (Euramet Project 1304) from 0.1 N·m to 5 N·m and from 5 N·m to 50 N·m	4
A two-capillary viscometer for temperatures up to 473 K and pressures up to 100 MPa—operation and verification at low pressure	4
CIPM key comparison CCPR-K1.a.2017 for spectral irradiance 250 nm to 2500 nm. Final report	4
Spectrophotometer-employed method for measuring luminous transmittance and haze	4
Assay of sodium carbonate	4
Bilateral comparison of irradiance scales between PMOD/WRC and PTB for longwave downward radiation measurements	4
Final report on EURAMET key comparison EURAMET.M.D-K2.2 (1523)	4
APMP key comparison of luminous intensity (APMP.PR-K3.a): final report	4
A Bayesian statistical method for large-scale MEMS-based sensors calibration: a case study on 100 digital accelerometers	4
Report on the key comparison, CCM.F-K23 in force at 200 N and 500 N	4
Key comparisons of air kerma and absorbed dose to water standards in 60Co radiation beam (EURAMET.RI(I)-K1.3 and EURAMET.RI(I)-K4.3)	4
Advancements in the NRC-FCs2 primary frequency standard	4
A constant pressure flowmeter for extreme-high vacuum	4
Practical realisation of the kelvin by Johnson noise thermometry	4
CCQM-P206, nitrous oxide (N2O) in air, ambient level, pilot study run in parallel with CCQM-K68.2019	4
Final report on the APMP regional comparison of type R thermocouples calibration at Cu, Co-C and Pd fixed points, APMP.T-S16	4
Key comparison BIPM.RI(I)-K5 of the air-kerma standards of the BEV, Austria and the BIPM in 137Cs gamma radiation	4
Measurement method of the solar diffuser bidirectional reflectance distribution function in the short-wave infrared band	4
International comparison CCQM-K3.2019 automotive exhaust gases	4
Monte Carlo uncertainty evaluation of gravimetric gas mixture with asymmetric distributions	4
Final report of CCQM-K96.2023.1: assay of potassium dichromate	4
Calibration of a step gauge (APMP.L-K5.n01)	4
Comparison report between NIM and CMS of the ITS-90 realization at the triple point of argon	4
Key comparison study - organic solvent calibration solution - gravimetric preparation and value assignment of deoxynivalenol (DON) in acetonitrile (ACN)	4
Key comparison BIPM.RI(I)-K8 of high dose-rate 192Ir brachytherapy standards for reference air kerma rate of the NIM and the BIPM	4
Properties of a definition of the SI second based on several optical transitions	3
Method to traceably determine the refractive index by measuring the angle of minimum deviation	3
A metrological framework for uncertainty evaluation in machine learning classification models	3
Speedy in-situ magnetic field compensation algorithm for multiple-channel single-beam SERF atomic magnetometers	3
Subsequent bilateral key comparison study - organic solvent calibration solution - gravimetric preparation and value assignment of aflatoxin B1 (AfB1) in acetonitrile (ACN)	3
Bilateral supplementary comparison of high voltage transformer measuring systems	3
APMP.QM-S19: Toxic elements in seafood	3
AFRIMETS supplementary comparison on pin gauges	3
CCQM-K176 breast cancer biomarker HER2 copy number variation (CNV) measurement	3
Comparison of primary standards for liquid flow - flow range (0.1 to 10) µL/min	3
What is measurement uncertainty? A discussion *	3
Measurement of average mass attenuation coefficient of air for 137Cs gamma-ray irradiation beam	3
Comment on ‘On the dimension of angles and their units’	3
New impedance bridge at LNE for the two terminal-pair AC resistor calibration up to 20 kHz	3
Strontium 1 S 0 → 1 P	3
Phase-stepping interferometry for parallelism measurement of step gauge faces	3
Phase transition behavior of pure Fe cells for thermocouple calibration	3
Realisation of the kilogram with the XRCD method – improved XRF evaluation and its impact	3
Characterization of laser-pumped Cs-4He atomic magnetometer	3
Activity measurements of the radionuclides 18F, 64Cu and 99mTc for the ANSTO, Australia, in the ongoing comparisons BIPM.RI(II)-K4 series and KCRV update in the corre	3
AFRIMETS supplementary comparison on calibration of dial gauge	3
Final report, ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with CMS/ITRI, March 2024	3
Extension to the range of prefixes for binary multiples	3
Experimental determination and Monte Carlo validation of 225 Ac absorbed dose	3
GPS PPP-AR frequency transfer and its application for comparing atomic fountain primary frequency standards between NRC and PTB	3
Comparison of laser power in multi-kilowatt range between three types of measurement systems based on light pressure or calorimetric principles	3
Comparison of methods to determine the fluence of monoenergetic neutrons in the energy range from 30 keV to 14.8 MeV	3
Force Key Comparison CCM.F-K2.a.2 - Final Report	3
International Comparison CCQM-K175 - Hydrogen chloride in nitrogen	3
Long-term stability of molecular doped epigraphene quantum Hall standards: single elements and large arrays (R K/236 ≈ 109 Ω)	3
APMP supplementary international comparison of activity measurement of Cs-134 and Cs-137 in brown rice	3
FINAL REPORT OF SIM SUPPLEMENTARY COMPARISON ON TESTING MACHINE CALIBRATION IN COMPRESSION UP TO 100 kN	3
Measurement of the intrinsic sensitivity for a single-ended accelerometer without the influence of the mounting condition	3
Reply to Comment on ‘On the dimension of angles and their units’	3

Final report of CCQM-K157 for the measurement of the amount of substance of HfO2 expressed as the thickness of nm films	3
Final report on key comparison APMP.AUV.A-K5	3
An assessment of the ageing of the absolute spectral responsivity of trap detectors at krypton ion laser emission wavelengths	3
Developing calibration and measurement capabilities for atmospheric CH4 stable isotope ratios at NMIs/DIs: metrology for global comparability	3
Comparison of standards for the calibration of stopwatches	3
Bilateral comparison of 1.018 V and 10 V standards between INRIM (Italy) and the BIPM, November to December 2023 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)	3
Calibration of an ionisation chamber for parent–progeny decay	3
Final report of CCQM-P204, comparison on CO2 isotope ratios in pure CO2	3
Comparison BIPM.RI(I)-K6 of the standards for absorbed dose to water of the ARPANSA, Australia, and the BIPM in accelerator photon beams	2
Calibration of angle standards	2
Noise-induced servo errors in optical clocks utilizing Rabi interrogation	2
Challenges in time and frequency metrology: accomplishments and overview of ongoing work	2
A robust time scale for space applications using the student’s t-distribution	2
ITS-90 SPRT calibration from the Ar TP to the Zn FP	2
Enhancing the UTCr algorithm: performance improvements and optimization	2
Explicit ensemble mean clock synchronization for optimal atomic time scale generation	2
Key comparison BIPM.RI(I)-K8 of high dose-rate 192Ir brachytherapy standards for reference air kerma rate of the VSL and the BIPM	2
Speed of sound measurements and derived third and fourth acoustic virial coefficients of supercritical neon	2
Bilateral comparison of 10 kΩ standards (ongoing BIPM key comparisons BIPM.EM-K13.b) between UME and the BIPM.	2
On-site comparison of Quantum Hall Effect resistance standards of the PTB and the BIPM: Ongoing key comparison BIPM.EM-K12	2
SIM.T-K9.3: Standard platinum resistance thermometer ITS-90 realizations from the Hg triple point to the Zn freezing point	2
Uncertainty analysis of MSL’s CCT-K7.2021 key comparison measurements taking account of correlations	2
Repeatability of a primary thermometer and calibration of resistance thermometers between 5 K and 25 K	2
PAWG pilot study on quantification of total haemoglobin in blood	2
Evaluating the effect of wavefront aberrations in an atom gravimeter*	2
CCQM-K158 elements and inorganic arsenic in rice flour	2
A test of measurement results with increased sensitivity to inconsistency	2
Bilateral comparison of 10 pF and 100 pF standards (ongoing BIPM key comparisons BIPM.EM-K14.a and 14.b) between the CENAM (Mexico) and the BIPM	2
Impact study of numerical discretization accuracy on parameter reconstructions and model parameter distributions	2
The isotopic composition of the new enriched silicon crystal Si28-31Pr11: maintaining the realization and dissemination of the mole and the kilogram via the XRCD method	2
International comparison CCQM-P229 pilot study to measure line intensities of selected 12C16O transitions	2
Evaluation of the relativistic redshift in frequency standards at KRISS	2
COOMET key comparison COOMET.PR-K1.a.2018 for spectral irradiance 250 nm to 2500 nmm, final report	2
Characterization of the collisional frequency shift in an atomic fountain clock using absorption imaging	2
Absolute frequency measurement of the 87Sr optical lattice clock at NTSC using international atomic time	2
Update of the BIPM comparison BIPM.RI(II)-K1.Mn-54 of activity measurements of the radionuclide 54Mn to include the 2024 result of the POLATOM (Poland)	2
Novel developments of refractive power measurement techniques in the automotive world	2
On the thermodynamic status of The Provisional Low Temperature Scale from 0.9 mK to 1 K , PLTS-2000, evaluated by primary thermometry	2
Evaluation of the long-term reproducibility of a realization of the kilogram by the XRCD method	2
Bilateral comparison of 1.018 V and 10 V standards between DEFNAT (Tunisia) and the BIPM, April to June 2022 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)	2
First international comparison of three different tabletop Kibble balances from 1 mg to 10 g	2
Primary calibration for airborne infrasound utilizing the vertical gradient of the ambient pressure	2
EURAMET.T-K9 regional key comparison ITS-90 SPRT calibration from the Ar TP to the Zn FP	2
Final report, on-going key comparison BIPM.QM-K1, ozone at ambient level, comparison with NIMT, September 2022	2
Calibration of two mass standards with the LNE Kibble balance in 2024	2
On modelling of artefact instability in interlaboratory comparisons	2
Continental-scale microwave frequency transfer via optical fiber: a 3143 km field deployment achieving 10 −17 stability	2
Supplementary comparisons of national standards of ratio error and phase displacement of AC voltage of power frequency COOMET 411/RU-a/07 (COOMET.EM-S6)	2
Report of subsequent key comparison CCQM - K73.2018.2 amount content of H+ in hydrochloric acid (0.1 mol/kg-1)	2
Second generation room-temperature dual-mode photodiodes with record-low uncertainties	2
Calibration of the microphone sensitivity below 0.5 Hz using the liquid-column-type sound pressure generator	2
Update of the BIPM comparison BIPM.RI(II)-K1.Ge-68 of activity measurements of the radionuclide 68Ge to include the 2021 result of the NIM (China)	2
Quantum plasmonic sensing by Hong–Ou–Mandel interferometry	2
A multi-gas, multi-pressure primary standard humidity calibration facility	2
Digital transformation in ionizing radiation metrology: advances and priorities	2
Comparison of partial discharge (PD) calibrators from 0.1 pC to 10 nC	2
Measurement of bidirectional transmittance distribution function in the visible and near-infrared spectral range	2
Results of the CCRI(II)-S16.Lu-177 International Supplementary Comparison of the Activity Measurements of a Solution of 177Lu	2
Improved systematic evaluation of a strontium optical clock with uncertainty below	2
Laser-based primary standard for absolute spectral irradiance calibration with predictable quantum efficient detectors	2
EURAMET supplementary comparison EURAMET.L-S26.1, measurement of groove depth standards in the range 5 μm up to 0.9 mm	2
Two-capillary viscometer for temperatures and pressures relevant to CO2 capture, transport, and storage—operation and improved analysis at high pressure	1
CCQM-K155: elements and tributyltin in seawater	1
Conversion of a piston–cylinder dimensional dataset to the effective area of a mechanical pressure generator	1
Second Comment on ‘The Avogadro constant is not the defining constant of the mole’	1
High-fidelity analysis of the electro-optical non-equivalence of planar electrical substitution radiometers*	1
CCQM Key Comparison track A CCQM-K168: Non-polar analytes in high carbohydrate food matrix: trans-zearalenone in maize powder	1
Report on key comparison AFRIMETS.AUV.V-K5 and linking to CCAUV.V-K5	1
Traceable methods for calibrating condensation particle counters at concentrations down to 1 cm−3	1
International comparison CCQM-K150: particle number concentration (100 to 20 000 cm-3) and particle charge concentration (0.15 to 3 fC cm-3)	1
Femtosecond-comb based 10 MHz-to-optical frequency link with uncertainty at the 10−18 level	1
Statistics for quantifying aging in time transfer system delays	1
On the rationale for recent updates to the SI Brochure concerning angles and quantities with the unit one	1
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	1
Trap induced broadening in a potential hydrogen lattice clock	1
Final report on EURAMET key comparison EURAMET.M.D-K2.1 (1522)	1
Calibrating the global network of gravitational wave observatories via laser power calibration at NIST and PTB	1
Instrumentation and uncertainty evaluation for absolute characterization of thin films and nanostructured surfaces in advanced optical metrology	1
Update of the BIPM comparison BIPM.RI(II)-K1.Cs-137 of activity measurements of the radionuclide 137Cs to include the 2014 result of the NRC (Canada) and the 2018 result of the TENMAK-NÜKEN	1
Supplementary comparison of national standard instruments in the field of magnetic flux density and magnetic flux measurements by sensing coils	1
Traceability for nuclear medicine: the status of primary radioactivity standards	1
CCQM-K160: platinum group elements in automotive catalyst	1
Final report, ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with NMC-A*STAR, July 2022	1
Final report, ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with UNAL-CALAIRE (November 2023)	1
Bilateral comparison in high gauge pressure 250 MPa	1
Accelerator-driven photon reference field for replacement of 137Cs γ-ray	1
AFRIMETS supplementary comparison on calibration of external micrometer	1
Thickness and refractive index measurements of a thin-film using an artificial neural network algorithm	1
Key comparison BIPM.RI(I)-K3 of the air-kerma standards of the PTB, Germany, and the BIPM in medium-energy x-rays	1
Subsequent key comparison of the pH of a borate buffer	1
Corrigendum: Corrections to a proposal for three categories of units within the SI (2024 Metrologia 61 033001)	1
Final report on the key comparison CCAUV.A-K6	1
Small mass value realization equivalent to accuracy class E1 using the Planck-Balance at PTB	1
Key comparison BIPM.RI(I)-K1 of the air-kerma standards of the NIST, USA and the BIPM in 60Co gamma radiation	1
COOMET regional comparison of the national standards of air kerma for x-radiation qualities used for radiation protection and diagnostic radiology (COOMET.RI(I)-S3)	1