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Miniature Signals and Miniature Counters: Accuracy Assurance Via Microprocessors and Multiparameter Control Techniques

  • L A Currie (a1), R W Gerlach (a1), G A Klouda (a1), F C Ruegg (a1) and G B Tompkins (a1)...

Abstract

When 14C signals approach background levels, the validity of assumptions concerning Poisson counting statistics and measurement system stability becomes crucial in interpreting the resultant low-level counting observations. This has been demonstrated in our previous work on detection limits for non-Poisson error and it is critical in our current studies of carbonaceous pollutants, where the 14C signal from just 5 mg C is comparable to that of the background for our miniature gas proportional counters. To assure data quality, our multi-detector system is designed for the on-line monitoring of critical parameters that reflect both the (statistical) nature of the non-Poisson errors and the underlying (physical) causes. It sends >60 bits of information/pulse to a microprocessor which automatically generates, for each counting period, two-dimensional spectra and multiparameter correlation and control charts. To evaluate the validity of long-term counting of 1–10 mg C we use robust (statistical) estimators, optimal counting interval subdivision, and time series analysis of the individual pulses. New opportunities for selective sampling and chemical fractionation which come with the small sample measurement capability have led us to give special attention also to higher control levels, involving e g, isotonic heterogeneity and representative standard materials.

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Copyright

References

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Cooper, JA, Currie, LA, and Klouda, GA, 1981, Assessment of Contemporary carbon combustion source contributions to urban air particulate levels using C-14 measurements: Environmental Sci Technol, v 15, p 1045.
Cooper, JA and Malek, D, eds, 1981, Conference on residential solid fuels, environmental impacts and solutions: Oregon Graduate Center, p 365385.
Cox, DR and Lewis, PAW, 1966, The statistical analysis of series of events: New York, Wiley & Sons, Chap 6.
Currie, LA, 1973, The limit of precision in nuclear and analytical chemistry: Nuclear Instruments Methods, v 100, p 387395.
Currie, LA, 1978, Bias Detection, in : New York, John Wiley and Sons, p 151.
Currie, LA, Klouda, GA, Continetti, RE, Kaplan, IR, Wong, WW, Dzubay, TG, and Stevens, RK, 1983, On the origin of carbonaceous particles in American Cities: Results of radiocarbon dating and chemical characterization, in Stuiver, M and Kra, RS, eds, Internatl 14C conf; Radiocarbon, v 25.
Currie, LA, Noakes, J, and Breiter, D, 1979, Measurement of small radiocarbon samples: Power of alternative methods for tracing atmospheric hydrocarbons, in Berger, R and Suess, HE, eds, Radiocarbon dating, Internatl 14C conf, 9th, Proc: Berkeley/Los Angeles, Univ California Press, p 158175.
Kafadar, K, Rice, J, and Spiegelman, C, 1983, One-sided trimming in small samples with asymmetric contamination: Commun in statistics, theory and methods, v 12, no. 4, p 477496.
Polach, HA, Soini, E, Kojola, H, Robertson, S, and Kaihola, L, 1982, Radiocarbon dating of milligram-size samples using gas proportional counters: an evaluation of precision and of design parameters, in Australian conf on archaeometry, 1st, Proc: Sydney, Australian Museum.
Sayre, EV, Harbottle, G, Stoenner, RW, Otlet, RL, and Evans, GB, 1981, The use of the small gas proportional counters for the carbon-14 measurement of very small samples, in : IAEA, Vienna, in press.

Miniature Signals and Miniature Counters: Accuracy Assurance Via Microprocessors and Multiparameter Control Techniques

  • L A Currie (a1), R W Gerlach (a1), G A Klouda (a1), F C Ruegg (a1) and G B Tompkins (a1)...

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