A Model for Analyzing Components of Uncertainty Encountered in {sup 3}H-Standard Efficiency Tracing in 4{pi}{beta} Liquid Scintillation Counting
Over the past decade, uniform conventions for assessing and reporting measurement uncertainties have been adopted by nearly every international metrological organization, as well as by many scientific and engineering associations and principal laboratories. This uncertainty approach is available as guidelines published by the International Organization for Standardization (ISO) and is used by the National Institute of Standards and Technology (NIST) for the dissemination of all of its standards, calibrations, and measurement results. One of the most widely used techniques for the radioactivity standardizations at NIST is liquid scintillation (LS) spectrometry, mainly through the use of a {sup 3}H-standard efficiency tracing technique that has come to be known as the CIEMAT/NIST method. Although the method is relatively simple in concept and implementation, correct analysis of the uncertainties involved in applying the method using ISO guidelines is not. An initial requirement for a proper uncertainty analysis is the development of a model that explicitly specifies the relationship between the different input and output variables involved in the measurement that lead to an uncertainty in the final certified activity. The approach taken in this analysis is based on the fact that use of black-box computer codes as an integral part of the calculation of a final value makes a formal mathematical expression of the measurement model difficult, if not impossible. Therefore, many of the uncertainty components were estimated by propagating the uncertainty from each of the respective components through the data reduction equations using a spreadsheet.
- Research Organization:
- National Institute of Standards and Technology, Gaithersburg, MD (US)
- Sponsoring Organization:
- none (US)
- OSTI ID:
- 787543
- Report Number(s):
- ISSN 0003-018X; CODEN TANSAO; ISSN 0003-018X; CODEN TANSAO; TRN: US0109417
- Resource Relation:
- Conference: 2000 International Conference on Nuclear Science and Technology: Supporting Sustainable Development Worldwide (2000 ANS Winter Meeting), Washington, DC (US), 11/12/2000--11/16/2000; Other Information: Transactions of the American Nuclear Society, Volume 83; PBD: 12 Nov 2000
- Country of Publication:
- United States
- Language:
- English
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