Main text This report describes a key comparison of mass standards APMP.M.M-K5, conducted between 19 participating members of the Asia-Pacific Metrology Programme (APMP). The APMP.M.M-K5 comparison was launched during the 13th meeting of the Technical Committee for Mass and Related Quantities APMP-TCM (2012).Two sets of stainless steel weights with five nominal mass values: 2 kg, 200 g, 50 g, 1 g, and 200 mg were used as travelling standards. These nominal values were chosen as they followed the nominal values of CCM.M-K5. The aim of the comparison is to verify the consistency of 2 kg, 200 g, 50 g, 1 g and 200 mg stainless steel mass standards among members of APMP-TCM. The program was piloted by the National Institute of Metrology, P.R. China (NIM). All the participants have provided their support and help to successfully organize and run the comparison. The nominated 19 participants have been divided into five petals and the corresponding five sets of transfer standards have been circulated within the groups simultaneously. The pilot laboratory measured the volumes and the magnetic properties of the standards before the circulation and had reported these values to the participants. The pilot laboratory has also verified the stability of all travelling standards for more than one year. The set of five weights was circulated among all the participating laboratories in August 2015 and received back from the last participant in August 2016. The final report of this comparison is being given in this document. To 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 https://www.bipm.org/kcdb/ . 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).

This report presents the comparison philosophy, methodology, analysis and the results of the designed CCM.D-K4 key comparison that covered the calibration of high resolution hydrometers for liquid and alcoholometers in the density range 600 kg/m 3 to 2000 kg/m 3 at the temperature of 20°C. The main purpose of this comparison was not only to evaluate the degree of equivalence in the calibration of high accuracy hydrometers between NMI participants, but also to link, were it is possible, the results of previous comparisons to Key Comparison Reference Values (KCRVs) of CCM.D-K4. Eleven NMI laboratories took part in the CCM.D-K4 divided in two groups (petals). With the CCM.D-K4 purpose, two similar sets consisting of three hydrometers for liquid density determinations and an alcoholometer were circulated to the NMI participants as a travelling standard in the time interval from January 2011 to April 2012. Twelve Key Comparison Reference Values (KCRVs) for each petal have been obtained at the density values related to the tested density marks of the transfer standards by the results of participants. The KCRVs and corresponding uncertainties were calculated by the weighted mean in the case of consistent results, otherwise the median was used. The degree of equivalence (DoE) with respect to the corresponding KCRV was determined for each participant and, in this particular comparison, the Weighted Least Squares (WLS) method was used to link the individual DoE of each participant by a continuous function. Significant drift of the transfer standards was not detected. This report also gives instructions on calculating pair-wise degrees of equivalence, with the addition of any information on correlations that may be necessary to estimate more accurately as well as the procedure for linking international comparisons to the CCM.D-K4. Finally an example of linkage to the CCM.D-K4 is given by dealing with the results of the bilateral comparison between INRiM and NMIA, which was added to this comparison so that all participants were engaged after the breakage of the 9340171 artefact. A particularly good agreement was found among the results provided by most of the participants, even if some systematic differences and either underestimated or overestimated uncertainties of the submitted results can be identified with respect to the KCRVs. In general the deviations of the laboratory results to the KCRVs are within of 1/3rd to 1/4th of a scale division and the uncertainty at 95% is usually within half a division. During the analysis of the submitted results, a systematic difference between the first and last immersed mark was also noted, possibly due to a temperature gradient along the stem and/or wetting of the stem around the tested mark, and therefore a corrected claimed uncertainty from each laboratory is expected. However this comparison may help the laboratories to solve some residual or marginal problems as well as to better understand the uncertainty components. The comparison fully supports the calibration measurement capabilities table in the BIPM key comparison database (KCDB). The results can be used to link regional comparisons to this CCM key comparison Main text To 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).

This report describes a key comparison of 1?kg stainless steel mass standards, CCM.M-K4, undertaken by the Consultative Committee for Mass and Related Quantities (CCM) Working Group on the Dissemination of the kilogram (WGD-kg). The CCM.M-K4 comparison was launched during the 12th meeting of the CCM (2010). The aim of the present comparison is to verify the consistency of 1?kg stainless steel mass standards among members of the CCM. The previous CCM 1?kg stainless steel mass standards comparison was carried out in 1995?1997 as the CCM.M-K1 comparison. The Bureau International des Poids et Mesures (BIPM) was the pilot laboratory for this key comparison. There were sixteen participants in the CCM.M-K4 comparison, all are CCM members. The comparison was structured into four petals with two stainless steel travelling mass standards per petal. The measurements and the reported results were completed in between one month and five months depending on the participants. One laboratory's results were found to be inconsistent with the other laboratories' results and one other laboratory gave a significant deviation from the key comparison reference value (KCRV). Both laboratories were contacted before preparation of the draft A report, without disclosing the details of the deviations, to allow them to check and revise their values. The fourteen other participants were in agreement with each other and degrees of equivalence have been established. Finally, the mass values of the eight stainless steel travelling standards were determined in air by the NMIs with claimed standard uncertainties ranging from 0.007 mg to 0.021 mg. Degrees of equivalence have been established by using the generalized linear least-squares estimation (GLS) method. The result demonstrates the high quality of this comparison and that some participants are able to provide, for their mass calibration services, standard uncertainties of around ten micrograms. The good uniformity of worldwide mass dissemination since the last periodic mass verification carried out in 1992 is demonstrated by the agreement among the NMIs' results. In addition, the observed weighted mean of the NMI deviations against the BIPM is ?0.0098 mg (? = 0.0036 mg). Despite the good result obtained in this particular comparison we should, in order to have a more accurate calibration system, improve the knowledge of the ageing effects of the mass references and increase the BIPM calibration frequency of the national prototypes. Main text. To 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).

This report describes a key comparison of 1 kg stainless steel mass standards, CCM.M-K4, undertaken by the Consultative Committee for Mass and Related Quantities (CCM) Working Group on the Dissemination of the kilogram (WGD-kg). The CCM.M-K4 comparison was launched during the 12th meeting of the CCM (2010). The aim of the present comparison is to verify the consistency of 1 kg stainless steel mass standards among members of the CCM. The previous CCM 1 kg stainless steel mass standards comparison was carried out in 1995-1997 as the CCM.M-K1 comparison. The Bureau International des Poids et Mesures (BIPM) was the pilot laboratory for this key comparison. There were sixteen participants in the CCM.M-K4 comparison, all are CCM members. The comparison was structured into four petals with two stainless steel travelling mass standards per petal. The measurements and the reported results were completed between one month and five months depending on the participants. One laboratory's results were found to be inconsistent with the other laboratories' results and one other laboratory gave a significant deviation from the key comparison reference value (KCRV). Both laboratories were contacted before preparation of this draft A, without disclosing the details of the deviations, to allow them to check and revise their values. The fourteen other participants were in agreement with each other and degrees of equivalence have been established. Finally, the mass values of the eight stainless steel travelling standards were determined in air by the NMIs with claimed standard uncertainties ranging from 0.007 mg to 0.021 mg. Degrees of equivalence have been established by using the Generalized Linear Least-Squares estimation (GLS) method. The result demonstrates the high quality of this comparison and that some participants are able to provide, for their mass calibration services, standard uncertainties of around ten micrograms. The good uniformity of world-wide mass dissemination since the last periodic mass verification carried out in 1992 is demonstrated by the agreement among the NMI's results. In addition, the observed weighted mean of the NMI deviations against the BIPM is -0.0098 mg (sigma = 0.0036 mg). Despite the good result obtained in this particular comparison we should, in order to have a more accurate calibration system, improve the knowledge of the ageing effects of the mass references and to increase the BIPM calibration frequency of the national prototypes.

This report describes a key comparison of 1 kg stainless steel mass standards, CCM.M-K4, undertaken by the Consultative Committee for Mass and Related Quantities (CCM) Working Group on the Dissemination of the kilogram (WGD-kg). The CCM.M-K4 comparison was launched during the 12th meeting of the CCM (2010). The aim of the present comparison is to verify the consistency of 1 kg stainless steel mass standards among members of the CCM. The previous CCM 1 kg stainless steel mass standards comparison was carried out in 1995-1997 as the CCM.M-K1 comparison. The Bureau International des Poids et Mesures (BIPM) was the pilot laboratory for this key comparison. There were sixteen participants in the CCM.M-K4 comparison, all are CCM members. The comparison was structured into four petals with two stainless steel travelling mass standards per petal. The measurements and the reported results were completed between one month and five months depending on the participants. One laboratory's results were found to be inconsistent with the other laboratories' results and one other laboratory gave a significant deviation from the key comparison reference value (KCRV). Both laboratories were contacted before preparation of this draft A, without disclosing the details of the deviations, to allow them to check and revise their values. The fourteen other participants were in agreement with each other and degrees of equivalence have been established. Finally, the mass values of the eight stainless steel travelling standards were determined in air by the NMIs with claimed standard uncertainties ranging from 0.007 mg to 0.021 mg. Degrees of equivalence have been established by using the Generalized Linear Least-Squares estimation (GLS) method. The result demonstrates the high quality of this comparison and that some participants are able to provide, for their mass calibration services, standard uncertainties of around ten micrograms. The good uniformity of world-wide mass dissemination since the last periodic mass verification carried out in 1992 is demonstrated by the agreement among the NMI's results. In addition, the observed weighted mean of the NMI deviations against the BIPM is -0.0098 mg (sigma = 0.0036 mg). Despite the good result obtained in this particular comparison we should, in order to have a more accurate calibration system, improve the knowledge of the ageing effects of the mass references and to increase the BIPM calibration frequency of the national prototypes.

This report summarizes the results of the bilateral key comparison APMP.M.M-K1.1 between the National Measurement Institute of Australia (NMIA) and the National Metrology Centre, Agency for Science Technology & Research (NMC, A*STAR) using a 1 kg stainless steel mass standard. The objective of the comparison is to demonstrate the metrological equivalence between the two laboratories. The results of the comparison will be used to support improved Calibration and Measurement Capability (CMC) declaration of NMC, A*STAR to fulfil the requirements of the CIPM MRA. The NMIA has taken part in both CCM.M-K1 and APMP.M.M-K1.1, and is the pilot and linking laboratory for this bilateral comparison. The comparison commenced on 29 September 2008 and was concluded on 15 December 2008. A stainless steel 1 kg OIML Class E1 standard mass was used as the travelling artefact and was transported between the laboratories by courier and by hand-carrying. The APMP.M.M.K2 technical protocol was adopted as the protocol for this comparison. The comparison results together with their assigned uncertainties show good agreement between NMIA and NMC, A*STAR and with the key comparison reference value (KCRV) of the CCM.M-K1. It also shows that NMC, A*STAR has the measurement capability at the OIML E1 level. The deviation from the KCRV of the CCM.M-K1 for NMC, A*STAR through this comparison is +0.033 mg with an uncertainty of 0.049 mg. Main text. To 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 (MRA).

This report summarizes the results of a comparison of mass standards conducted between eleven participating members, including the pilot laboratory, of the Asia-Pacific Metrology Program (APMP). One set of five weights with nominal mass values 10 kg, 500 g, 20 g, 2 g and 100 mg were used as traveling artifacts. These nominal values were chosen as they followed the nominal values of CCM.M-K2. The program was piloted by the National Physical Laboratory, New Delhi, India (NPLI), and the Center for Measurement Standards, Industrial Technology Research Institute (CMS-ITRI), Taiwan, Korea Research Institute of Standards and Science (KRISS), Korea, and Measurement Standards Laboratory (MSL), New Zealand, have provided all other help to successfully organize and run the comparison. The set of five weights was circulated among all the participating laboratories in July 2004 and received back from the last participant in March 2007. The final report of this comparison is being given in this document. Main text. To 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 (MRA).

The results are presented of key comparison CCM.P-K2 that covered the pressure range 10 kPa to 120 kPa in absolute mode. Nine national measurement institutes participated in the comparison, which used a piston-cylinder assembly of 335 mm nominal effective area as a transfer standard.Whilst not all laboratories were found to be equivalent at all pressures, the larger-than-expected instabilities in the transfer standard precluded the ability to discriminate between participants' standards at a level needed to fully support the Calibration Measurement Capabilities table in the BIPM key comparison database.