System and method for measuring retentate in filters

A system for determining the contaminant material loading of a filter, wherein said contaminant material has a dielectric constant different from the first dielectric constant of said filter, comprising:

• a metallic container forming a resonant cavity, housing the said filter, wherein said filter is positioned in the cavity to remove contaminant material from a flow;
• a frequency generator, outputting a signal having a frequency range so as to encompass multiple resonance modes of said cavity;
• at least one antenna to transmit said signal from said frequency generator into said cavity;
• at least one antenna to receive said transmitted signal from said cavity;
• and
• a controller that compares parameters of said received signal to a reference, and that determines, based on said comparison, said contaminant material loading;
• wherein said controller further determines a spatial distribution of the contaminant material in the filter.

A method for determining the contaminant material loading of a filter, contained within a container forming a resonant cavity, wherein said filter has a first dielectric constant and the contaminant material has a second dielectric constant different from said first dielectric constant, the method comprising:

• selecting a region of interest for monitoring contaminant material accumulation in the filter located within the cavity;
• selecting a frequency range suitable to generate at least one cavity resonant mode corresponding to said region of interest, based on the cavity geometry and dielectric properties;
• establishing microwave energy in the cavity over the selected frequency range to establish said at least one cavity resonant mode;
• monitoring changes in the cavity microwave response at said at least one cavity resonant modes;
• determining contaminant material loading based on the changes in the cavity microwave response at said resonant mode,
• wherein said determining contaminant material loading comprises determining local accumulation of the material in said region of interest.