RISS 검색 - 국내학술지논문 상세보기

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다국어 초록 (Multilingual Abstract)

We determined accurate values of ratios among the average molar masses MAr of 9 argon samples using two completely-independent techniques: (1) mass spectrometry and (2) measured ratios of acoustic resonance frequencies. The two techniques yielded mutually consistent ratios (RMS deviation of 0.16 ？ 10−6 MAr from the expected correlation) for the 9 samples of highly-purified, commercially-purchased argon with values of MAr spanning a range of 2 ？ 10−6 MAr. Among the 9 argon samples, two were traceable to recent, accurate, argon-based measurements of the Boltzmann constant kB using primary acoustic gas thermometers (AGT). Additionally we determined our absolute values of MAr traceable to two, completely-independent, isotopic-reference standards; one standard was prepared gravimetrically at KRISS in 2006; the other standard was isotopically-enriched 40Ar that was used during NIST’s 1988 measurement of kB and was sent to NIM for this research. The absolute values of MAr determined using the KRISS standard have the relative standard uncertainty ur(MAr) = 0.70 ？ 10−6 (Uncertainties here are one standard uncertainty.); they agree with values of MAr determined at NIM using an AGT within the uncertainty of the comparison ur(MAr) = 0.93 ？ 10−6. If our measurements of MAr are accepted, the difference between two, recent, argon-based, AGT measurements of kB decreases from (2.77 ？ 1.43) ？ 10−6 kB to (0.16 ？ 1.28) ？ 10−6 kB. This decrease enables the calculation of a meaningful, weighted average value of kB with a uncertainty ur(kB) ≈ 0.6 ？ 10−6.