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Sampling with discrete contamination

Lyman, Geoffrey and Bourgeois, Florent Sampling with discrete contamination. (2011) In: 5th World Conference on Sampling and Blending (WCSB5), 25-28 Oct 2011, Santiago, Chile .

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Abstract

The sampling variance for a process stream which carries fluctuating levels of the sought-after analyte and is subject to mass flow variation can be estimated from the covariance function of the analyte fluctuation and the covariance function of the mass flow when these covariance functions are well-defined and can be considered to be a stationary property of the process stream. However, in the case of sampling a flow of material (a one-dimensional lot) or from material removed from the hold of a ship (a three-dimensional lot) which does not possess a covariance function for the analyte of interest, a different approach must be taken. An important example of such a case is a shipment of grain that is contaminated by some component such as genetically modified organisms (GMOs) or by mycotoxins. Depending on the manner of contamination, the regions of the lot that carry contamination can be considered as randomly located distributions of concentration. The distributions themselves may be stochastic in that their mean concentrations and extents may be statistically defined rather than fixed. This paper develops the sampling variance for ‘slugs’ of contamination with a uniform concentration distribution and regular spacing of the sample increments, based on the assumption that the origins of the slugs are uniformly and randomly located (a Poisson point process).

Item Type:Conference or Workshop Item (Paper)
Audience (conference):International conference proceedings
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS
Université de Toulouse > Institut National Polytechnique de Toulouse - INPT
Other partners > Materials sampling & consulting Pty Ltd (AUSTRALIA)
Université de Toulouse > Université Paul Sabatier-Toulouse III - UPS
Laboratory name:
Laboratoire de Génie Chimique - LGC (Toulouse, France) - Génie des Interfaces & Milieux Divisés (GIMD)
Statistics:download
Deposited By: Florent BOURGEOIS

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