Combining data from independent chemical analysis methods

Schiller, Susannah B.; Eberhardt, Keith R.

doi:10.1016/0584-8547(91)80164-x

Cited by 47 publications

(28 citation statements)

References 1 publication

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“…At this juncture it seems appropriate to recommend an updated value to the isotope geology community. Holden (1990) and others (Schiller and Eberhardt, 1991;Pommé et al, 2008) have cautioned against underestimating errors in individual experiments as well as taking weighted averages of results of experiments of fundamentally different types. Counting experiments, geological age-comparisons, and ingrowth measurements have their own independent systematic errors.…”

Section: K 87 In the Context Of Other Recent Measurementsmentioning

confidence: 97%

Determination of the decay-constant of 87Rb by laboratory accumulation of 87Sr

Rotenberg¹,

Davis²,

Amelin³

et al. 2012

Geochimica et Cosmochimica Acta

102

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Section: K 87 In the Context Of Other Recent Measurementsmentioning

confidence: 97%

Determination of the decay-constant of 87Rb by laboratory accumulation of 87Sr

Rotenberg¹,

Davis²,

Amelin³

et al. 2012

Geochimica et Cosmochimica Acta

102

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“…The certified values for Na, K, Mg, Ca, Ba, Cu, Zn, Fe, Mn, Cd, Pb, Co and Ni in rice flour based on 95 % confidence limit of the mean and the computation of the weighted mean and its uncertainty as proposed from NIST 23,25,26 are presented in Table 3. Vanadium and chromium were detected by only ICP-MS method, so only reference values were given in Table 4.…”

Section: Results Of Voltammetric Methodsmentioning

confidence: 99%

Untitled

Chuachuad¹,

Shiowatana²,

Chukanchanapituk³

et al. 2002

ScienceAsia

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An in-house reference material for trace metals in rice flour was produced. Certification of concentrations of fifteen elements based on at least two independent methods was carried out. The analytical techniques included ICP-AES, ICP-MS, ETAAS, FAAS and voltammetry. Out of the 15 elements, 13 elements, namely Na, K, Mg, Ca, Ba, Cu, Zn, Fe Mn, Co, Ni, Pb and Cd, could be certified whereas only reference values were given to Cr and V because the concentrations of these two elements were so low that only one analysis method could successfully detect them. Statistical tests for the study of homogeneity at 95 % confidence level did not reveal significant differences between the within-bottle and between-bottle variation. The rice flour material is considered to be homogeneous at 250-650 mg sample sizes. No significant change was observed in a long-term stability study of the material over a period of 5 months and a short-term stability study at an elevated temperature of 50 °C for a period of 5 weeks. A comparison of results obtained from independent methods was made before certified values were calculated using both means and weighted means. The reference materials have been distributed for use in laboratory quality assurance.

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“…Documentation and procedures for acquiring this software are available at the Internet address http://www.itl.nist.gov/div898/software/dataplot/homepage.htm. The consensus mean analysis computes estimates of the consensus mean, and the associated uncertainties, based on all of the comparison data using a variety of methods [5][6][7][8][9].…”

Section: Key Comparison Reference Values (Kcrv) Based On Comparison Dmentioning

confidence: 99%

“…Let these values be normalized to the appropriate mean NIST pair responses, where the term "mean NIST pair response" is discussed in the paragraph presenting Eq. (7). For Transducer 1, the normalized differences and standard uncertainties are…”

Section: Kcrv Calculation From Combined Data For Multiple Transducersmentioning

confidence: 99%

Final report on force key comparison CCM.F-K4.a and CCM.F-K4.b for 4 MN and 2 MN forces

Bartel¹

2012

Metrologia

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This report gives the results for the Comité International des Poids et Mesures (CIPM) key comparisons in force, designated by comparison numbers CCM.F-K4.a and CCM.F-K4.b, for the maximum force values of 4 MN and 2 MN, respectively. Eight National Metrology Institutes, employing nine national force standard machines, participated in these comparisons. The National Institute of Standards and Technology (NIST) served as the pilot institute for these comparisons. Four transducers were employed in two star circulations, with one pair circulated among the participants of CCM.F-K4.a and the other pair circulated for CCM.F-K4.b. The transducers exhibited only minor drift over the circulation time periods; however, the results for one of the transducers circulated for CCM.F-K4.a were limited by excessive sensitivity to orientation about the axis of force application.Two analysis approaches for calculating Key Comparison Reference Values (KCRV) are presented, one employing a classical consensus mean analysis and the other based on weighted mean calculations. Reasonable correlation in the conclusions for individual transducers is seen between the two approaches. The weighted mean approach is extended to yield a KCRV for each of the two force values from the combined data from all of the associated transducers. One of the seven participants at 4 MN, and two of the nine participants at 2 MN, have expanded uncertainty intervals that lie outside of the expanded uncertainty bands for the corresponding weighted mean KCRVs.

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Combining data from independent chemical analysis methods

Cited by 47 publications

References 1 publication

Determination of the decay-constant of 87Rb by laboratory accumulation of 87Sr

Determination of the decay-constant of 87Rb by laboratory accumulation of 87Sr

Untitled

Final report on force key comparison CCM.F-K4.a and CCM.F-K4.b for 4 MN and 2 MN forces

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