Measurement of Uncertainty for Aqueous Ethanol Wet-Bath Simulator Solutions Used with Evidential Breath Testing Instruments
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Rong-Jen Hwang [1] ; Jada Beltran [1] ; Craig Rogers [1] ; Jeremy Barlow [1] ; Gerasimos Razatos [1]
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[1] Toxicology Bureau Scientific Laboratory Division New Mexico Department of Health Albuquerque NM
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- Localización: Journal of forensic sciences, ISSN-e 1556-4029, ISSN 0022-1198, Vol. 61, Nº. 5, 2016, págs. 1359-1363
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
Aqueous ethanol wet-bath simulator solutions are used to perform calibration adjustments, calibration checks, proficiency testing, and inspection of breath alcohol instruments. The Toxicolog y Bureau of the New Mexico Department of Health has conducted a study to estimate a measurement of uncertainty for the preparation and testing of these wet-bath simulator solutions. The measurand is identified as the mass concentration of ethanol (g/100 mL) determined through dual capillary column headspace gas chromatography with flame ionization detector analysis. Three groups were used in the estimation of the aqueous ethanol wet-bath simulator solutions uncertainty: GC calibration adjustment, GC analytical, and certified reference material. The standard uncertainties for these uncertainty sources were combined using the method of root-sum-squares to give uc= 0.8598%. The combined standard uncertainty was expanded to U = 1.7% to reflect a confidence level of 95% using a coverage factor of 2. This estimation applies to all aqueous ethanol wet-bath simulator solution concentrations produced by this laboratory.
