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D. BUTLER, Epsilon Industrial Incorporated, 2215 Grand Avenue Parkway, Austin, TX 78728

In the course of attempting to make a reliable and repeatable in-line measurement, there are several factors in the process that can affect the desired result. These might include, but are not limited to; process temperature, density, color, flow-rate, particle size, pump turbulence and air entrainment. Careful consideration should be taken in selecting the best technology available to make these measurements. Guided Microwave Spectrometry (GMS)is a unique approach for performing multi-constituent analysis of materials whose makeup exhibits one or more of the above problem issues. The composition of the process can be inferred with knowledge of a material's complex permittivity or dielectric constant. The material under test is placed in, or flows through a measurement chamber that mimics a section of RF waveguide. The scalar response of the waveguide is measured over a wide bandwidth at wavelengths long enough to mitigate errors that can be introduced by reflections due to particular size. Due to the unique transitional shape of the chamber, the electromagnetic energy is kept within the waveguide thereby minimizing upstream and down stream turbulence effect. The parameters that are scrutinized arc the DC value of the dielectric constant (e', Epsilon prime), the DC value of the conductivity (s, Sigma), and the molecular relaxation time (t, Tau ). With the GMS technique, multiple component analysis becomes possible. Excellent results have been obtained in measuring moisture, protein and fat in various meat emulsions. Success has also been achieved in measuring moisture in harvested grains, ground corn, process cereals, dough's and candy coatings.