Key Comparison Reference Value Research Articles

CCM.FF-K3.2011.1: CIPM key comparison of air speed, 0.5 m/s to 40 m/s

The bilateral key comparison between PTB and VNIIM (CCM.FF-K3.2011.1) was performed as direct follow-up of the CIPM air speed key comparison (CCM.FF-K3.2011) which was organized to determine the degree of equivalence of the national standards for air speed covering the range 0.5 m/s to 40 m/s under ambient conditions. An ultrasonic anemometer and a laser Doppler anemometer were used as transfer standards. The measurement procedures in the technical protocol as well as the transfer standards for the bilateral key comparison (CCM.FF-K3.2011.1) were identical to the CIPM Key Comparison (CCM.FF-K3.2011) with nine participants from three RMOs. Thus, the measurement results were directly linked to the key comparison reference values published in the final report of the (CCM.FF-K3.2011) for each standard and each air speed separately. The degree of equivalence of each result with the key comparison reference value (KCRV) was calculated. All reported results of the bilateral key comparison were consistent with the KCRV results of the (CCM.FF-K3.2011).Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Volume comparison at 100 μL—calibration of micropipettes

An inter-comparison in the calibration of micropipette was conducted among 12 different National Metrology Institutes between 2014 and 2016. Three 100 μL micropipettes were supplied as transfer artifacts. However, one of the three micropipettes did not fulfil the stability assessment criterion and therefore it was excluded from the inter-comparison. The other two micro pipettes were transferred among the participants. The results reported by the participants were corrected to the standard atmospheric pressure to ensure that the comparison is conducted under approximately the same conditions. The key comparison reference value and its standard uncertainty were calculated as a weighted mean from the results reported by the participants. The outlier values were handled throughout the iterative chi-square consistency check method where only one result was excluded from the calculation of the reference value. Except only one participant's results, the results reported by the other participants were in consistent with the key comparison reference value.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

The results of CCM.G-K2.2017 key comparison

The CCM.G-K2.2017 comparison was organised for the purpose of determination of the degree of equivalence of the national standards for free-fall acceleration measurement. The comparison was held in the Changping Campus of National Institute of Metrology China (NIM), from October to November in 2017. This is the first time that such a comparison is organized outside of the Europe continent and establishes a new global comparison sites in China. This comparison is also the largest ever organized with the participation of 13 instruments.We give the list of the participants who actually performed measurements during the comparison, the data (raw absolute gravity measurements and their uncertainties) submitted by the participants as well as the results of the vertical gravity gradient at the comparison sites. The measurement strategy is briefly discussed and the data elaboration is presented. Finally, the results of the data adjustment are presented including the degrees of equivalence (DoE) of the absolute gravimeters and the key comparison reference values (KCRVs). Overall, the measurements of KC instruments are all consistent given the declared uncertainties.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

APMP key comparison of absolute pressure from 10 kPa to 110 kPa (APMP.M.P-K9)

This report describes the results of a key comparison of pneumatic pressure standards which was carried out at fourteen National Metrology Institutes (NMIs: NMIA, NSCL, PTB, NIM, VMI, CMS/ITRI, MSL, NMIJ/AIST, NMC A*STAR, NIMT, SCL, NIS, RCM-LIPI and KRISS) during the period of February 2010 to July 2012 within the framework of the Asia-Pacific Metrology Programme (APMP) in order to determine their degrees of equivalence at pressures in the range 10 kPa to 110 kPa in absolute mode. Among them, twelve NMIs' results were compared in the report. The pilot laboratory was Korea Research Institute of Standards and Science (KRISS). The degrees of equivalence in this comparison were transferred to the corresponding CC key comparison, CCM.P-K2. National Measurement Institute, Australia (NMIA) and Physikalisch-Technische Bundesanstalt (PTB) that participated in the CC comparison agreed to be link laboratories.Most of the participating institutes used pneumatic pressure balances as their pressure standards while two link laboratories used laser interferometer mercury manometers. Precise absolute pressure gauges were used as transfer standards (TSs). The precision pressure gauge has two Quartz-Resonant Pressure Transducers (Q-RPTs) inside. Two identical transfer packages (TS-A and TS-B) were circulated independently to reduce the time required for the measurements. During the comparison, intermediate measurements of two circulated transfer standards were carried out in the pilot laboratory after one or two NMIs measurement and third transfer standard (TS-C) was monitored for the stability characterization, also. The pressures of the comparison were (10, 30, 50, 70, 90, 100, 110) kPa. From the calibration results, the behaviours of the transfer standards during the comparison period were well characterized and it was concluded that the performance of the transfer standards were sufficient in the comparison pressure range except 10 kPa. The TSs used in this comparison were not suitable for the low pressure measurement like 10 kPa because of low display resolution of TS (1 part in 105 at 10 kPa). The degrees of equivalence of each national measurement standard were expressed quantitatively by two terms, deviations from the key comparison reference values (KCRVs) and pair-wise differences of their deviations together with the associated uncertainties. The pneumatic pressure standards in the range 30 kPa to 110 kPa for absolute mode of all participating NMIs were found to be equivalent within their claimed uncertainties.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Key comparison EURAMET.PR-K2.a.2011—spectral responsivity in the range of 900 nm to 1600 nm

The Euramet.PR-K2.a comparison on spectral responsivity for the wavelength range 900 nm to 1600 nm, as described in this report, was carried out to establish the degree of equivalence for the participating European laboratories with respect to the Key Comparison Reference Value (KCRV) of the CCPR-K2.a-2003 comparison. Seven laboratories, including pilot and link laboratory, participated. The comparison was piloted by VSL (Netherlands). Both VSL and NPL (UK) act as link laboratories to the CCPR-K2.a-2003 comparison.Most laboratories show a DoE within 1 % from the CCPR KCRV for almost the full wavelength range, with some slightly larger differences mostly above 1450 nm. One laboratory shows larger deviations, up to 3%.This report provides an overview of the comparison, a description of the characterization of the reference detectors, the data-analysis, participant results and their uncertainties and the degree of equivalence of participating laboratories with the CCPR KCRV. The full Technical Reports of the participants are included in the Appendix of the comparison report.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCPR, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

EURAMET.M.P-K15.1

In the present comparison, the degrees of equivalence of the measurement standards for vacuum pressures from 3E-4 Pa up to 1 Pa of three NMIs were evaluated by comparison with the measurement standards PTB serving as linking laboratory to the two key comparisons CCM.P-K15 and CCM.P-K4. The three NMIs were IMT, Slovenia, NIMT, Thailand and TUBITAK-UME, Turkey. Two spinning rotor gauges served as transfer standards and showed a very good stability. All NMIs and at all pressures showed equivalence with the key comparison reference values of CCM.P-K15 and CCM.P-K4. Another NMI, CEM, Spain, took part in the comparison, but did not deliver any data.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Final report for GULFMET.M.M-K4: key comparison of 1 kg stainless steel mass standards

This report summarizes the results of the key comparison (KC) carried out among eight National Metrology Institutes (NMIs) and an Accredited Calibration Laboratory, six of which are member countries of Gulf Association for Metrology (GULFMET). The KC of two 1 kg stainless steel knob weights was decided during the 11th meeting of GULFMET TC Mass held in Abu Dhabi, 2017. TÜBİTAK UME (Turkey) acted as pilot laboratory. The comparison was linked to CCM.M-K4 via INRIM (Italy), METAS (Switzerland), KRISS (Republic of Korea). The results were evaluated by the generalized least square (GLS) estimation. Majority of results were consistent with each other and with the key comparison reference value of CCM.M-K4 within their expanded uncertainties with the coverage factor of k = 2.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Final report for GULFMET.M.M-K7: key comparison of 5 kg, 100 g, 10 g, 5 g and 500 mg mass standards

This report summarizes the results of the key comparison (KC) carried out among seven National Metrology Institutes (NMIs) five of which are member countries of Gulf Association for Metrology (GULFMET). The KC of 5 kg, 100 g, 10 g, 5 g stainless steel knob weights and 500 mg nickel silver flat pentagonal shaped weight was decided during the 11th meeting of GULFMET TC Mass held in Abu Dhabi, 2017. TÜBİTAK UME (Turkey) acted as pilot laboratory. The comparison was linked to CCM.M-K7 via INRIM (Italy) and METAS (Switzerland). The results were evaluated by the generalized least square (GLS) estimation. Majority of results were consistent with each other and with the key comparison reference value of CCM.M-K7 within their expanded uncertainties with the coverage factor of k = 2.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral key comparison of INMETRO and INTI humidity standards in the dew/frost-point temperature range from -30 °C to +60 °C (SIM.T-K6.7)

The aim of this paper is to describe a bilateral comparison carried out by the hygrometry laboratories of the National Metrological Institutes of Brazil and Argentina, INMETRO and INTI, respectively. The comparison, registered as a bilateral key comparison of the Inter American Metrology System (SIM) as SIM.T-K6.7 - INMETRO/INTI, was performed in the range from -30 °C to 60 °C of dew/frost-point temperatures. This paper presents the facilities of the laboratories, the measurement procedures, the uncertainty analysis, the compatibility of the measurement results (by means of the normalised error and by the degree of equivalence) and the degree of equivalence for the dew-point temperatures 1 °C and 20 °C between INTI and the CCT-K6 key comparison reference value by means of a previous comparison between INMETRO and the National Institute of Standards and Technology (NIST).Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Final report of the key comparison of Vickers hardness: APMP.M.H-K1.b and APMP.M.H-K1.c

This report describes the results of first APMP key comparison on Vickers hardness, APMP.M.H-K1b and APMP.M.H-K1c involving Seven member institutes, CMS/ITRI (Chinese Taipei), KRISS (Korea, Republic of), NIM (China), NMIJ/AIST (Japan), NIMT (Thailand), SCL (Hong Kong, China) and VMI (Vietnam). The pilot laboratory was NMIJ/AIST. Three institute, KRISS, NIM and NMIJ/AIST, act as linking institutes to the key comparisons CCM.H-K1b and CCM.H-K1c conducted for the Vickers hardness scales HV1 and HV30, respectively.The comparison was also conducted for HV 10 Vickers hardness scales and it was conducted as the supplemental comparison item.The comparison item is Vickers hardness for 200 HV 1, 200 HV 10, 200 HV 30, 600 HV 1, 600 HV 10, 600 HV 30, 900 HV 1, 900 HV 10, and 900 HV 30. Through this comparison, the results for 200 HV 1, 600 HV 1 and 900 HV 1 scales are linked to CCM.H-K1b, and the results for 200 HV 30, 600 HV 30 and 900 HV 30 scales are linked to CCM.H-K1c. The reference values were calculated by using weighted mean from the results of the institutes. The Degree of Equivalence (DoE) was indicated by the relative deviation from the reference values. All institute results showed in good agreement to the key comparison reference values of CCM.H-K1b and CCM.H-K1c.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

BIPM comparison BIPM.RI(II)-K1.Fe-59 of activity measurements of the radionuclide 59Fe for the PTB (Germany), LNE-LNHB (France) and the NMIJ (Japan), and the linked APMP.RI(II)-K2.Fe-59 comparison

Three new participations in the BIPM.RI(II)-K1.Fe-59 comparison have been added to the previous results and this has produced a revised value for the key comparison reference value (KCRV), calculated using the power-moderated weighted mean. A link has been made to the APMP.RI(II)-K2.Fe-59 comparison held in 2014 through the NMIJ who participated in both comparisons. Five NMIs used the K1 or K2 comparison to update their degree of equivalence. The degrees of equivalence between each equivalent activity measured in the International Reference System (SIR) and the KCRV have been calculated and the results are given in the form of a table for the remaining five NMIs in the BIPM.RI(II)-K1.Fe-59 comparison and the eight other participants in the APMP.RI(II)-K2.Fe-59 comparison. A graphical presentation is also given.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Report of APMP comparison of the activity measurements of Fe-59 (APMP.RI(II)-K2.Fe-59)

The international comparison of activity measurements of 59Fe, APMP.RI(II)-K2.Fe-59, was carried out within the framework of the Asia-Pacific Metrology Programme (APMP). Nine institutes took part in the comparison, and eight institutes of them undertook absolute measurements. One ampoule prepared using the same radioactive solution as that used in the comparison was sent to the BIPM/SIR in order to link the comparison to the BIPM key comparison reference value (KCRV).Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

CCQM-K137, nitrogen monoxide (NO) in nitrogen

The key comparison CCQM-K137 was aimed at evaluating the level of compatibility of laboratories' preparative capabilities for gravimetric nitrogen monoxide/nitrogen primary reference mixtures at mole fractions of 30 μmol mol-1 and 70 μmol mol-1.The comparison was organised by the BIPM. It consisted in the simultaneous comparison of a suite of 2n primary gas standards, two standards to be prepared by each of the n participating laboratories at the nominal values of 30 μmol mol-1 and 70 μmol mol-1. Two independent analytical methods were used by the BIPM to analyse the amount fraction of nitrogen monoxide (NO) in nitrogen; UV spectrophotometry and chemiluminescence (CLD). The agreement between the results obtained with the two main techniques served to highlight possible issues in the preparation of the standards. During this comparison, standards prepared by two participants appeared to result in a larger bias between the analysers than observed for others. These observations were explained by the analysis of all standards by Fourier Transform Infrared Spectroscopy (FTIR) which identified the presence of a larger amounts of water vapour (H2O), nitrous oxide (N2O) and nitrogen dioxide (NO2) in these standards, which are the three main impurities which can appear in mixtures of NO in nitrogen.The above observations were used to underpin the selection of standards (at each nominal NO mole fraction) which can be considered as a consistent set, allowing the calculation of a calibration line by a Generalised Least-Square regression. Key Comparison Reference Values were then proposed for all participants as predicted values from the calibration lines. Interferences caused in the response of the CLD analyser by impurities (verified by FTIR measurements) led to only the results from the UV analyser being proposed for the KCRV and Degrees of Equivalence calculations. Good agreement was observed between all participants who could prepare their standards with minimum levels of impurities.The key comparison CCQM-K137 is considered to present an analytical challenge at both nominal mole fractions and therefore considered as a Specialised (Track C) comparison in the CCQM nomenclature.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Zea maize reference materials for genetically modified organism detection in Mexico.

Zea maize reference materials for genetically modified organism detection in Mexico.

The first official measurement of 11C in the SIRTI

In the summer of 2017, the Système International de Référence Transfer Instrument (SIRTI) of the Bureau International des Poids et Mesures (BIPM) was hosted by the National Research Council of Canada (NRC) in Ottawa, Canada. This SIRTI visit was unique in many aspects. It was the first visit of the SIRTI to Canada. NRC was the first National Metrological Institute (NMI) to perform comparisons of four isotopes (99mTc, 18F, 64Cu and 11C) during a single two-week period. Finally, this was the first official measurement of 11C in the SIRTI.The NRC had performed a primary standardization of 11C in February of 2017 and calibrated its Secondary Standard Ionizing Radiation Chamber System (SSIRCS) in preparation for the SIRTI comparison. Two primary Liquid Scintillation methods (CIEMAT/NIST and TDCR) were employed and the results agreed. The stock material was received from a local cyclotron in the form of a 11C-labelled sodium acetate (NaC2H3O2). Three ampoules were prepared for the purposes of comparison; one concentrated from the bulk material and two derived from a single dilution. Some inconsistency was evident due to a weighing problem for one of the ampoules containing the diluted solution, whose measurements were excluded from the analysis. The other two ampoules’ results were consistent within their respective uncertainties. The SIRTI was very stable and the final BIPM report will detail the stability checks, performance and behaviour of the SIRTI during its measurement campaign in Canada.There is still no Key Comparison Reference Value (KCRV) for 11C as NRC is the first participant. However, during a test of the SIRTI at NPL in 2014, an equivalent SIRTI activity was measured as 9.87(5) kBq which was consistent with MonteCarlo predictions for 11C in the SIRTI of 9.867(15) kBq. The NRC SIRTI equivalent activity for 11C agrees within uncertainty with these results. This offers encouragement to other NMIs to request a 11C comparison given the consistency of experimental results from NRC and test results from the National Physical Laboratory, UK (NPL) and the BIPM.Finally a half-life measurement was determined from the NRC measurement of multiple half-lives of a 11C ampoule and was found to be 20.332(40)min. From the SIRTI measurements at NRC, the half-life was derived as 20.328(13) min. This is smaller but consistent with the DDEP recommended value of 20.361(23)min.

Statistical reassessment of calibration and measurement capabilities based on key comparison results

According to the CIPM mutual recognition arrangement, a calibration and measurement capability (CMC) uncertainty for a laboratory offering a particular calibration or measurement service is normally expressed at a 95 % level of confidence. When laboratories’ CMC claims are unsupported by the relevant key comparison (KC), after publishing the final report of the KC, modified values may have to be assigned to their CMC uncertainties. In many cases when CMCs apply to a continuous interval of values such as mass fraction or wavelength, KCs are carried out for selected discrete values of the quantity concerned. Since the comparison at each discrete value may only support the CMC uncertainty at that point, it is not immediately apparent how to modify the CMC uncertainties. Under realistic assumptions, we developed a method that is applicable in such an instance and for which the reported CMC uncertainties are amplified so that they are underpinned by the results of the KC. The amplification factors depend on the laboratories’ degrees of equivalence (DoEs) for these discrete values, judiciously adjusted to achieve consistency with the key comparison reference values. The method is based on the patterns in the individual behaviour of the DoEs of the participating laboratories for the discrete values, implying the presence of correlation associated with the DoE values. It applies when the weighted mean of some or all of the measured values reported by the participating laboratories in the KC is used to obtain the KC reference value.

Main Results of COOMET.EM-K5 Key Comparison of Power

The COOMET.EM-K5 Key Comparison of Power was carried out in the CIPM–MRA framework from 2016 to 2018. The main aims of this project were to compare national measurement standards of low-frequency 50/60 Hz power and to link with the CCEM-K5 Key Comparison. This comparison was carried out between 13 National Metrology Institutes which are the members of five Regional Metrology Organisations: COOMET, EURAMET, APMP, GULFMET and AFRIMET. The selected travelling standard of low-frequency 50/60 Hz power was compared at: UMTS (Ukraine), BelGIM (Belarus), VNIIM (Russia), GeoSTM (Georgia), CMS (Kyrgyzstan), UME (Turkey), SMU (Slovakia), LEM-FEIT (R. Macedonia), NIM (China), MASM (Mongolia), QCC EMI (UAE), SASO-NMCC (Saudi Arabia), and NIS (Egypt). UMTS was a pilot laboratory. NIM (China) and VNIIM (Russia) were linking National Metrology Institutes for the linking process between CCEM-K5 Key Comparison and COOMET.EM-K5 Key Comparison due of participating in CCEM-K5 Key Comparison.The paper is devoted to the discussion of issues concerning the participation and further evaluation of measurement data of COOMET.EM-K5 Key Comparison of Power. Main results of participating laboratories measuring the same power of travelling standard of low-frequency 50/60 Hz power in a framework of COOMET.EM-K5 Key Comparison of Power are presented. Besides, the paper describes some problems concerning the evaluation of travelling standard drift effect and its further influence on evaluation of Key Comparison Reference Value during a Key Comparison. Degrees of Equivalence and Expanded Uncertainties of National Metrology Institutes participants are set. In addition, En number was calculated for each National Metrology Institute participating in COOMET.EM-K5 Key Comparison of Power with the aim of determining data consistency.

High polarity analytes in biological matrix: determination of urea and uric acid in human serum (CCQM-K109)

The CCQM Organic Analysis Working Group (OAWG) agreed on a Track A comparison for the measurement of polar organic in biological matrix as part of its 10-year strategic plan. As a model for this comparison, two polar clinical biomarkers: urea and uric acid, in human serum were chosen. This comparison was designed to enable participating National Metrology Institutes (NMIs) or Designated Institutes (DIs) to demonstrate their measurement capabilities in the determination of analytes with molecular mass of 50 to 500 g/mol, having the polarity pKOW > 2 in the range of 10 to 2,000 mg/kg in a biological matrix such as human serum, blood and urine. Two pools of human serum materials with different concentration levels of urea and uric acid were used as the comparison materials. Fifteen NMIs/DIs participated in this Track A comparison. All of them submitted the results for urea and 14 NMIs/DIs submitted the results for uric acid. With the exception of one NMI, all participating institutes employed isotope dilution mass spectrometry (IDMS) for the measurement of both urea and uric acid. Protein precipitation, liquid-liquid extraction and/or clean-up were applied, followed by instrumental analyses using GC-HRMS, GC-MS/MS, GC-MS, LC-HRMS, LC-MS/MS, LC-MS or HPLC-DAD. The Laplacian weighted medians were used as the Key Comparison Reference Values (KCRVs). The assigned KCRVs were the weighted medians of 13 results for urea (both serum pools), 10 results for uric acid (Serum I) and 11 results for uric acid (Serum II). Urea (Serum I) was assigned a KCRV of 1,486.0 mg/kg with a standard uncertainty of 9.0 mg/kg, urea (Serum II) was assigned a KCRV of 334.7 mg/kg with a standard uncertainty of 1.8 mg/kg, uric acid (Serum I) was assigned a KCRV of 136.50 mg/kg with a standard uncertainty of 0.98 mg/kg, and uric acid (Serum II) was assigned a KCRV of 39.39 mg/kg with a standard uncertainty of 0.11 mg/kg. The degree of equivalence (with the KCRV) and its uncertainty were calculated for each result. The majority of the participating institutes in CCQM-K109 demonstrated their capabilities in the measurement of the clinical markers in the biological matrix using IDMS.KEY WORDS FOR SEARCHClinical biomarkers; urea; uric acid; human serum, IDMSMain textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Final Report on Key Comparison SIM.QM-K27: Ethanol in Aqueous Matrix

Within the SIM RMO, certain NMIs/ DIs have indicated the need to demonstrate their measurement capability for the determination of ethanol in aqueous matrices. Reflecting upon the current situation, the SIM Chemical Metrology Working Group (CMWG) conducted a second regional Key Comparison in 2016 linked to the CCQM-K27, SIM.QM-K27. The RMO Key Comparison SIM.QM-K27 was coordinated by INMETRO, who demonstrated capability in the CCQM-K27.2 subsequent study: determination of ethanol in aqueous media. INMETRO also coordinated the first SIM RMO Key Comparison SIM.QM-K1. For SIM.QM-K27, two levels of ethanol in water solutions were gravimetrically prepared by INMETRO with a concentration range between 0.5 mg/g and 5 mg/g. The gravimetric value of the aqueous ethanol solutions was used to link SIM.QM-K27 to the CCQM-K27 Key comparison reference value (KCRV). The gravimetric values for SIM.QM-K27 Level 1 and Level 2 were (0.814 ± 0.008) mg/g (U k =2 ) and (3.818 ± 0.038) mg/g (U k =2 ), respectively. The KCRV was determined using the purity-corrected gravimetric preparation values. The KCRV uncertainty was assigned as 1 % from the reference values in order to give the same uncertainty as in the CCQM-K27.2 comparison. Fourteen laboratories took part in this regional KC, from SIM and other RMOs. One participant (INACAL) did not send results and thus it's capability was not evaluated. Ten of the thirteen participants in the SIM.QM-K27 demonstrated their ability to measure ethanol in aqueous matrix in the concentration range of 0.5 mg/g to 5 mg/g (both levels). One participant (ISP) demonstrated its ability to measure ethanol in aqueous matrix only at the low level (0.5 to 1.5 mg/g) and another participant (INM) demonstrated its ability to measure ethanol in aqueous matrix only at the high level (1.5 to 5.0 mg/g). NIMT did not demonstrate its ability to measure ethanol in aqueous matrix from 0.5 mg/g to 5 mg/g (both levels). The abilities demonstrated by the participants should be indicative of their ability to provide reference measurements for ethanol content in aqueous samples for both forensic and commodities applications. This report presents the results of the SIM Key comparison SIM.QM-K27. Successful participation in SIM.QM-K27 demonstrates the following measurement capabilities in determining mass fraction of ethanol in mass fraction range from 0.5 mg/g to 5 mg/g in an aqueous matrix.KEY WORDS FOR SEARCHKey comparison and ethanol in waterMain textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Linking the results of the regional key comparison EURAMET.AUV.V-K3 to those of the CIPM key comparison CCAUV.V-K3

During 2014 and 2015, fourteen national metrology institutes (NMI) took part in the CIPM key comparison CCAUV.V-K3 on the primary calibration of the complex voltage sensitivity of an accelerometer in the low frequency range. The five Euramet participants in this comparison had also participated in the RMO comparison EURAMET.AUV.V-K3 involving a total of ten Euramet NMIs. The results of the five CIPM participants have been used to link the results of the remaining five NMIs to the results in the CIPM key comparison. The degrees of equivalence between the result for each NMI and the key comparison reference value (KCRV) has been calculated and the results are given in the form of a matrix and graph for the ten Euramet NMIs.KEY WORDS FOR SEARCHAccelerometer, vibration calibration, low frequency rangeMain textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).