Final report of CCM key comparison of mass standards CCM.M-K6, 50 kg

Abstract

In order to show equivalence in mass standards calibration among National Metrology Institutes of member countries of the 'Comité international des poids et mesures' (CIPM), key comparisons of mass standards have been carried out under the auspices of the 'Comité Consultatif pour la Masse et les Grandeurs Apparentées' (CCM).This key comparison on 50 kg standards in standard stainless steel was based on the decision of the CCM during the 11th meeting held in April 2008 at the 'Bureau International des Poids et Mesures' (BIPM).For this key comparison CENAM—Mexico acted as pilot laboratory, and NPL—United Kingdom accepted to be co-pilot laboratory.The aims of this key comparison were to compare the results obtained by NMIs in calibration of 50 kg stainless steel weights and to repeat the exercise realized in 2001–2002 with the key comparison identified as CCM.M-K3. 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 CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Comparison of KCRV and Its Uncertainty of CCM Key Comparisons by Monte Carlo Method

“…There is a minor difference in calculating the correction in two KC's pilot labs. KC-K6 used the correction with respect to the pilot lab and the KCRV is around zero [9]. If the correction is followed by KC-K3's procedure for the pilot lab, KC-K6's KCRV of MCM could be modified to about -1.02 mg as marked by asterisk (*) in Table 2 and KCRV by GUF is still valid.…”

“…The results of six CCM KCs, CCM.M-K1-K6 have been published in history of mass metrology [4][5][6][7][8][9]. In this paper, we have tried to investigate with the raw data of CCM.M-K3 (KC-K3) and CCM.M-K6 (KC-K6) to get the insights of difference between GUM uncertainty framework (GUF) and Monte Carlo method (MCM), and between uncertainty evaluations according to various estimators.…”

Bayesian hypothesis testing for key comparisons

“…Such strong assumptions are not valid in all key comparisons. For example, the common measurand may show a deterministic [38] or a random [14] drift, there may be several measurands involved [39], or measurements are carried out in dependence on a controlled parameter such as frequency [40] or wavelength [41]. In these cases, more complicated statistical models than (1) are required, depending on the particular application.…”