24.10.2011
The results of an international comparison measurement ("Key Comparison") for the mass determination of mass standards with nominal values between 200 mg and 2 kg have been published this year. All measurement results determined by PTB agree with the reference values within the measurement uncertainties stated.
The results of the international comparison measurement CCM.M-K5 which was carried out under the auspices of the Comité Consultatif pour la Masse et les Grandeurs Apparantées (CCM), have been published this year . Responsible pilot laboratory was - with support of the Bureau International des Poids et Mesures (BIPM) and PTB - the National Metrology Institute of Japan (NMIJ). Twenty national metrology institutes were appointed as participants and divided into four groups. To allow the results of the participants for mass determinations of multiples and submultiples of the unit of mass to be compared, the pilot laboratory had five sets of standards at its disposal. Each set consisted of two mass standards with the nominal values 200 mg, 1 g, 50 g, 200 g and 2 kg. For the execution of the measurements, each group received one set of standards. One set remained at the pilot laboratory to control the stability of the transfer standards. Before and after each measuring cycle, the mass of the transfer standards was determined at the pilot laboratory. The masses of the transfer standards were determined by PTB with expanded measurement uncertainties (k = 2) in a range from 0.0004 mg (for 200 mg) to 0.056 mg (for 2 kg). All measurement results of PTB agree with the reference values within the measurement uncertainties stated.
References:
[1] I. van Andel et al.: Report on CIPM key comparison of the second phase of multiples and submultiples of the kilogram (CCM.M-K5). Metrologia 48 (2011), Tech. Suppl., 07008, CCM.M-K5 Final Report, 40 pages
Contact person:
Michael Borys, Dept. 1.1, WG 1.11, E-Mail: michael.borys@ptb.de