A MATHEMATICAL-MODEL FOR THE MULTIELECTRODE CAPACITANCE SENSOR

A model for the relationship between local permittivity variation and capacitance change is presented. The model is applicable to multi-elec trode capacitance sensors which have recently been used for tomographi c imaging of multi-phase processes. An explicit formula is derived for the relationship between permittivity in a small spherical region and sensor response. The predictions from this model are compared with re sults from a high-precision finite element simulation. Good agreement is shown. A simple tomographic reconstruction algorithm which uses thi s sensor model is introduced. Results show that accurate reconstructio n of permittivity distribution is possible for certain test cases.