An overview of electrical tomographic measurements in pharmaceutical and related application areas.

Tomographic measurement techniques offer the opportunity to quantify the degree of homogeneity of particulate suspensions and other multiphase mixtures. Electrical resistance tomography is a relatively simple and inexpensive technique for measuring the distribution of electrical conductivity within multiphase systems. This can provide pertinent information about the physical form, the chemical composition, or the general status of manufacturing. In this contribution, we present recent applications of this technology to processes in pharmaceutical and related application areas. Examples include on-line measurement of solids distribution in stirred tanks and crystallizers, monitoring the performance of an industrial pressure filter, and flow profile and velocity measurements in a physical model of a catalytic reactor.