We recently derived a very general representation formulafor the boundary voltage perturbations caused by internalconductivity inhomogeneities of low volume fraction (cf. Capdeboscq and Vogelius (2003)). In this paper we show how thisrepresentation formula may be used to obtain veryaccurate estimates for the size of the inhomogeneitiesin terms of multiple boundary measurements. As demonstrated by our computational experiments, these estimates are significantly better than previously known (single measurement) estimates,even for moderate volume fractions.
