Measuring the dielectric permittivity of filter cakes

The filter cake is prepared by filtering a suspension through a small section of coaxial waveguide. This approach produces the cake in place and eliminates the need for cutting and transferring the sample into the measurement cell. The sample section is attached to an air line and RF connector on each side to form a dielectric cell. The cell scattering parameters (RF transmission coefficients and reflection coefficients) are used to derive the permittivity and conductivity of the sample. For kaolinite filter cakes, there is excellent consistency between the dielectric parameters derived from individual scattering parameters. (Original abstract-amended)