Metrologia

Article	Citations
Adoption of ICRU report 90 recommendations in the Canadian Co-60 air-kerma primary standard	125
Key comparison CCQM-K179 - polar analyte in solid organic material: mass fraction of oxytetracycline hydrochloride salt	45
SIM supplementary comparison on calibration of conventional mass of a 20 kg weight	42
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	29
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)	26
Final report on the EURAMET key comparison EURAMET AUV.V-K5	24
SIM Thermocouple Type S Supplementary Comparison	23
Comparison of calibration of multimeter	21
Key comparison of voltage unit standards based on the Josephson effect	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)	19
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	19
Measurement of melting and freezing temperature of iron using radiation thermometry	18
Final report, ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with EMPA, June 2023	17
Report on EURAMET supplementary comparison on measurement of a 1 mm stage micrometer	17
Corrigendum: Detection and identification of faults in clock ensembles with the generalized likelihood ratio test (2022 Metrologia 59 045010)	16
Reply to Comment on ‘The Avogadro constant is not the defining constant of the mole’	16
Absolute frequency measurement of a Lu+ (3D1) optical frequency standard via link to international atomic time	15
Final report of CCQM-K96.2023: assay of potassium dichromate	14
Low-frequency calibration of accelerometers by rotation in the gravitational field at NIST	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
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 of APMP.AUV.V-S1: supplementary comparison on calibration of laser tachometers using mechanical generators	14
Relating SI units to the ‘defining constants’	13
CIPM key comparison of viscosity CCM.V-K4	13
CORRIGENDUM: Angles in the SI—a practical dimensional metrologist viewpoint * (2026 Metrologia  63 013	13

Detection and identification of faults in clock ensembles with the generalized likelihood ratio test	13
APMP key comparison of AC-DC current transfer standards: final report	13
Comparison of low air speed facilities	13
Characterization of the LED filament lamp for luminous intensity calibration	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	12
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
Economic optimization of acceptance interval in conformity assessment: 1. Process with no systematic effect	11
Discussion on the calculation of the uncertainties of [UTC-UTC(k)]	11
Autocollimators: plane angle measurand ambiguities and the impact of surface form	11
Comparison of blackbody for clinical infrared ear thermometers	10
Corrigendum: Uncertainty of the measurement of the frequency dependence of four-terminal pair capacitance with a four-channel vector network analyzer (2025 Metrologia	10
Key comparison BIPM.RI(I)-K7 of the air-kerma standards of the BFKH, Hungary, and the BIPM in mammography x-rays	10
International Comparison CCQM-K10.2018.1 - BTEX gas mixtures	10
Key comparison BIPM.RI(I)-K5 of the air-kerma standards of the GUM, Poland and the BIPM in 137Cs gamma radiation	10
High polarity analyte(s) in aqueous media: Determination of L-PFOA and L-PFOS in ground water	9
Evaluations of the decay data of 40 K, 45 Ti, 56	9
NTSC SrII optical lattice clock with uncertainty of 2	9
CCM.G-K2.2023: CIPM key comparison of absolute gravimeters	9
Series connection of quantum Hall resistance array and programmable Josephson voltage standard for current generation at one microampere	9
Key comparison CCQM-K148.b - polar analyte in solid organic material: mass fraction of oxytetracycline	8
Reply to Second Comment on ‘The Avogadro constant is not the defining constant of the mole’	8
Gas viscosities from a semiconductor-manufacturing mass-flow controller	8
The unusual status of the hectare in the SI	8
Machine learning based priors for Bayesian inversion in MR imaging	8
Traceable characterisation of fibre-coupled single-photon detectors	8
Final report for CCQM-P212: coherence of carbon isotope delta reference materials	8
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
Total radiant flux measurement of UV LEDs using a gonio-spectroradiometer	8
Accurate characterisation of optical diffuse transmission—primary facility and extension to translucent samples	7
A proposal for three categories of units within the SI	7
Applying heat transport modelling to reduce measurement uncertainty of the LASP reference standard NACR8 *	7
Ambient humidity, the overlooked influencer of radioactivity measurements	7
Application of a bandwidth correction method to thin-film reflectance measurements	7
A simple tool for weighted averaging of inconsistent data sets	7
Phase shifting angle interferometer	7
Measurement model of circadian action factor of phosphor-converted white LEDs based on photometric, electrical, and thermal properties	7
Final report on the CCM key comparison of kilogram realizations CCM.M-K8.2021	6
Key comparison CCEM.RF-K27.W of RF power from 50 GHz to 75 GHz in rectangular waveguide	6
Room temperature dual-mode internal quantum deficiency measurement with propagated uncertainty to 0.03% (k = 2)	6
Method for traceable calibration of 5G NR measuring receivers	6
Power of a test for assessing interlaboratory consensus of nominal and ordinal characteristics of a substance, material, or object	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
A new interpolation equation in the ITS-90 subrange from the triple point of water to the freezing point of indium	6
Multi-taper-based automatic correction of non-anechoic antenna measurements	6
Evaluation of the transportable atom gravimeter HUST-QG	6
Linkage for Metrosert to CCT-K9 via the EURAMET-T.K9.1 bilateral comparison	6
Precise high resistance comparison between the NMIJ traveling dual source bridge and the NIST adapted Wheatstone bridge	5

Precision measurement of an electron pump at 2 GHz; the frontier of small DC current metrology	5
Comparison of PLTS-2000 and the magnetic field fluctuation thermometer at LNE-Cnam	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
Corrigendum: Accuracy evaluation of primary frequency standard NIST-F4 (2025 Metrologia  62 035002)	5
AFRIMETS.AUV.A-S2 final report, calibration of a multi-function acoustic calibrator	5
Erratum: Metrological characterization of a commercial single-photon source with high photon flux emission (2024 Metrologia 61 054001)	5
Final report, ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with NIST, July 2022	5
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)	5
Pilot study CCQM-P172 – spectroscopic methods for HNO3 value assignment	5
Final report, On-going Key Comparison BIPM.QM-K1, Ozone at ambient level, comparison with NIM Oct.2023	5
Measurement science meets the reproducibility challenge	5
Precision control of resistive power in Kibble balance coils: an advanced method for minimizing temperature-related magnetic errors	5
Calibration of GNSS stations for UTC	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
Evaluations of the decay data of 57 Co, 76 Br, 133m	5
Final report of SIM supplementary comparison on testing machine calibration in compression up to 100 kN.	5
Continuous GPS PPP-AR frequency transfer links	5
First evaluation of the primary frequency standard NTSC-CsF2	5
Report on the key comparison, CCM.F-K23 in force at 200 N and 500 N	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
APMP key comparison of luminous intensity (APMP.PR-K3.a): final report	4
A proposal to change the leap-second adjustments to coordinated universal time	4
Assay of sodium carbonate	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
A two-capillary viscometer for temperatures up to 473 K and pressures up to 100 MPa—operation and verification at low pressure	4
Practical realisation of the kelvin by Johnson noise thermometry	4
Advancements in the NRC-FCs2 primary frequency standard	4
Monte Carlo uncertainty evaluation of gravimetric gas mixture with asymmetric distributions	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
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
Report of the comparison BIPM.QM-K2.b, on carbon dioxide in nitrogen at ambient levels, with E+ E Elektronik (2025)	4
Continuous IPPP links for UTC	4
CCQM-P206, nitrous oxide (N2O) in air, ambient level, pilot study run in parallel with CCQM-K68.2019	4
Bilateral comparison of irradiance scales between PMOD/WRC and PTB for longwave downward radiation measurements	4
Calibration of a step gauge (APMP.L-K5.n01)	4
Calibration of an ionisation chamber for parent–progeny decay	4
Final report of CCQM-K96.2023.1: assay of potassium dichromate	4
Spectrophotometer-employed method for measuring luminous transmittance and haze	4
A constant pressure flowmeter for extreme-high vacuum	4
Key comparison study - organic solvent calibration solution - gravimetric preparation and value assignment of deoxynivalenol (DON) in acetonitrile (ACN)	4
A Bayesian statistical method for large-scale MEMS-based sensors calibration: a case study on 100 digital accelerometers	4
Measurement method of the solar diffuser bidirectional reflectance distribution function in the short-wave infrared band	4
Lunar reference timescale	4
Final report on EURAMET key comparison EURAMET.M.D-K2.2 (1523)	4
International comparison CCQM-K3.2019 automotive exhaust gases	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
CIPM key comparison CCPR-K1.a.2017 for spectral irradiance 250 nm to 2500 nm. Final report	4
Comparison report between NIM and CMS of the ITS-90 realization at the triple point of argon	4
Comparison of primary standards for liquid flow - flow range (0.1 to 10) µL/min	3
Long-term stability of molecular doped epigraphene quantum Hall standards: single elements and large arrays (R K/236 ≈ 109 Ω)	3
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	3
Final report on key comparison APMP.AUV.A-K5	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
Comment on ‘On the dimension of angles and their units’	3
Final report of CCQM-P204, comparison on CO2 isotope ratios in pure CO2	3
GPS PPP-AR frequency transfer and its application for comparing atomic fountain primary frequency standards between NRC and PTB	3
Final report, ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with CMS/ITRI, March 2024	3
Phase transition behavior of pure Fe cells for thermocouple calibration	3
Characterization of laser-pumped Cs-4He atomic magnetometer	3
AFRIMETS supplementary comparison on calibration of dial gauge	3
Extension to the range of prefixes for binary multiples	3
Final report of CCQM-K157 for the measurement of the amount of substance of HfO2 expressed as the thickness of nm films	3
What is measurement uncertainty? A discussion *	3
An assessment of the ageing of the absolute spectral responsivity of trap detectors at krypton ion laser emission wavelengths	3
Measurement of the intrinsic sensitivity for a single-ended accelerometer without the influence of the mounting condition	3
Measurement of average mass attenuation coefficient of air for 137Cs gamma-ray irradiation beam	3
Force Key Comparison CCM.F-K2.a.2 - Final Report	3
Comparison of standards for the calibration of stopwatches	3
International Comparison CCQM-K175 - Hydrogen chloride in nitrogen	3
FINAL REPORT OF SIM SUPPLEMENTARY COMPARISON ON TESTING MACHINE CALIBRATION IN COMPRESSION UP TO 100 kN	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
Realisation of the kilogram with the XRCD method – improved XRF evaluation and its impact	3
Method to traceably determine the refractive index by measuring the angle of minimum deviation	3
AFRIMETS supplementary comparison on pin gauges	3
Developing calibration and measurement capabilities for atmospheric CH4 stable isotope ratios at NMIs/DIs: metrology for global comparability	3
Phase-stepping interferometry for parallelism measurement of step gauge faces	3
New impedance bridge at LNE for the two terminal-pair AC resistor calibration up to 20 kHz	3
Comparison of methods to determine the fluence of monoenergetic neutrons in the energy range from 30 keV to 14.8 MeV	3

Bilateral supplementary comparison of high voltage transformer measuring systems	3
Experimental determination and Monte Carlo validation of 225 Ac absorbed dose	3
Properties of a definition of the SI second based on several optical transitions	3
Subsequent bilateral key comparison study - organic solvent calibration solution - gravimetric preparation and value assignment of aflatoxin B1 (AfB1) in acetonitrile (ACN)	3
APMP.QM-S19: Toxic elements in seafood	3
CCQM-K176 breast cancer biomarker HER2 copy number variation (CNV) measurement	3
Regional comparison SIM.QM-S5 - natural gas	2
Calibration of the microphone sensitivity below 0.5 Hz using the liquid-column-type sound pressure generator	2
On-site comparison of Quantum Hall Effect resistance standards of the PTB and the BIPM: Ongoing key comparison BIPM.EM-K12	2
Bilateral comparison of 10 kΩ standards (ongoing BIPM key comparisons BIPM.EM-K13.b) between UME and the BIPM.	2
Speed of sound measurements and derived third and fourth acoustic virial coefficients of supercritical neon	2
Comparison of partial discharge (PD) calibrators from 0.1 pC to 10 nC	2
Results of the CCRI(II)-S16.Lu-177 International Supplementary Comparison of the Activity Measurements of a Solution of 177Lu	2
Evaluating the effect of wavefront aberrations in an atom gravimeter*	2
PAWG pilot study on quantification of total haemoglobin in blood	2
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
Evaluation of the long-term reproducibility of a realization of the kilogram by the XRCD method	2
Reply to Comment on ‘On the dimension of angles and their units’	2
Uncertainty analysis of MSL’s CCT-K7.2021 key comparison measurements taking account of correlations	2
A metrological framework for uncertainty evaluation in machine learning classification models	2
Report of subsequent key comparison CCQM - K73.2018.2 amount content of H+ in hydrochloric acid (0.1 mol/kg-1)	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
Continental-scale microwave frequency transfer via optical fiber: a 3143 km field deployment achieving 10 −17 stability	2
Letter case pairs for SI prefix symbols	2
Calibration of angle standards	2
Eight-element polarisation independent transmission trap detector with high attenuation	2
Primary calibration for airborne infrasound utilizing the vertical gradient of the ambient pressure	2
Enhancing the UTCr algorithm: performance improvements and optimization	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
A robust time scale for space applications using the student’s t-distribution	2
SIM.T-K9.3: Standard platinum resistance thermometer ITS-90 realizations from the Hg triple point to the Zn freezing point	2
Laser-based primary standard for absolute spectral irradiance calibration with predictable quantum efficient detectors	2
Final report, on-going key comparison BIPM.QM-K1, ozone at ambient level, comparison with NIMT, September 2022	2
EURAMET supplementary comparison EURAMET.L-S26.1, measurement of groove depth standards in the range 5 μm up to 0.9 mm	2
A test of measurement results with increased sensitivity to inconsistency	2
Second generation room-temperature dual-mode photodiodes with record-low uncertainties	2
APMP supplementary international comparison of activity measurement of Cs-134 and Cs-137 in brown rice	2
Evaluation of the relativistic redshift in frequency standards at KRISS	2
Noise-induced servo errors in optical clocks utilizing Rabi interrogation	2
COOMET key comparison COOMET.PR-K1.a.2018 for spectral irradiance 250 nm to 2500 nmm, final report	2
Quantum plasmonic sensing by Hong–Ou–Mandel interferometry	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
NRC measurement set-up and preparatory work for CCT-K7.2021 key comparison of triple-point-of-water cells	2
Impact study of numerical discretization accuracy on parameter reconstructions and model parameter distributions	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
Calibration of two mass standards with the LNE Kibble balance in 2024	2
Improved systematic evaluation of a strontium optical clock with uncertainty below	2
Novel developments of refractive power measurement techniques in the automotive world	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
Repeatability of a primary thermometer and calibration of resistance thermometers between 5 K and 25 K	2
EURAMET.T-K9 regional key comparison ITS-90 SPRT calibration from the Ar TP to the Zn FP	2
CCQM-K158 elements and inorganic arsenic in rice flour	2
Measurement of bidirectional transmittance distribution function in the visible and near-infrared spectral range	2
On modelling of artefact instability in interlaboratory comparisons	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
Speedy in-situ magnetic field compensation algorithm for multiple-channel single-beam SERF atomic magnetometers	2
ITS-90 SPRT calibration from the Ar TP to the Zn FP	2
Explicit ensemble mean clock synchronization for optimal atomic time scale generation	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
International comparison CCQM-P229 pilot study to measure line intensities of selected 12C16O transitions	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
A digital framework for realising the SI—a proposal for the metre	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
Subsequent key comparison of the pH of a borate buffer	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
Femtosecond-comb based 10 MHz-to-optical frequency link with uncertainty at the 10−18 level	1
Final report, ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with NMC-A*STAR, July 2022	1
CCQM-K155: elements and tributyltin in seawater	1
On the rationale for recent updates to the SI Brochure concerning angles and quantities with the unit one	1
Final report on EURAMET key comparison EURAMET.M.D-K2.1 (1522)	1
High-fidelity analysis of the electro-optical non-equivalence of planar electrical substitution radiometers*	1
AFRIMETS supplementary comparison on calibration of external micrometer	1
Two-capillary viscometer for temperatures and pressures relevant to CO2 capture, transport, and storage—operation and improved analysis at high pressure	1
Final report on the key comparison CCAUV.A-K6	1
Corrigendum: Corrections to a proposal for three categories of units within the SI (2024 Metrologia 61 033001)	1
Small mass value realization equivalent to accuracy class E1 using the Planck-Balance at PTB	1
CCQM-K160: platinum group elements in automotive catalyst	1
Bilateral comparison in high gauge pressure 250 MPa	1
Trap induced broadening in a potential hydrogen lattice clock	1
Conversion of a piston–cylinder dimensional dataset to the effective area of a mechanical pressure generator	1
Key comparison BIPM.RI(I)-K1 of the air-kerma standards of the NIST, USA and the BIPM in 60Co gamma radiation	1
Bilateral comparisons of reference switching impulse voltage measuring systems COOMET 707Ru-a16 (COOMET_EM-S21)	1
Thickness and refractive index measurements of a thin-film using an artificial neural network algorithm	1
Corrigendum: Thermal neutron reference radiation facility with high thermalization and large uniformity area (2023 Metrologia  60 045002)	1
Final report for SIM.QM-S12: supplementary comparison for trace elements in natural water	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
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
Final report, ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with UNAL-CALAIRE (November 2023)	1
Economic optimization of acceptance interval in conformity assessment: 2. Process with unknown systematic effect	1
Instrumentation and uncertainty evaluation for absolute characterization of thin films and nanostructured surfaces in advanced optical metrology	1
Accelerator-driven photon reference field for replacement of 137Cs γ-ray	1
New beta primary standard (BPS2) and revised ISO 6980 at PTB	1