Field sampling, uncertainty related

Field investigations never give a total picture of the contaminant situation. Usually, the number of samples in relation to the size of the contaminated site will merely indicate the existing situation. Only by using an experienced team of remediation specialists (hydrogeologists, chemists, soil specialists, etc.) will it be possible to minimize the uncertainties and thus the risks. 

The dielectric properties of a material are properly specified by a symmetric second-rank tensor relating the three components of the electrical displacement vector D to those of the field E. By choosing axes naturally related to the crystal structure the six independent components of this tensor can be reduced to three and, taking account of the hexagonal symmetry of the ice crystal, only two independent components remain. These are the relative permittivities parallel and perpendicular to the unique c-axis direction and we shall denote them by e, and e. We shall discuss the experimental determination of these quantities when we come to consider dielectric relaxation, since some difficulties are involved. For the present we simply note the results which are shown in fig. 9.2. The often-quoted careful measurements of Auty Cole (1952) were made with polycrystalline samples and removed many of the uncertainties in earlier work. They represent, however, a weighted mean of the values of e, and Humbel et al. (1953 [Pg.201]

The draft document defines three grades of accuracy with specified levels of uncertainty for each grade. Since the level of uncertainty in the measurements is related to the soimce noise field, the background noise field, and the sampling and meastmement procedures, initial procedures are proposed that determine the accuracy of the measurements. These procedures evaluate the Field Indicators that indicate the quality of the sound power measurements. These field indicators consider, among other things ... 

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