Patent ID: 6225812
Filing Date: 2001-05-01
Classification: G01N

Abstract:
Method of measuring the weight of a substance traveling continuously in a production process, the method comprising the steps of:providing a first sensor having a first aperture extending therethrough, the first sensor defining a resonant cavity and having circuitry operatively connected therewith, the circuitry being operatively connected to a processor for measuring a dielectric constant measurement corresponding to the density of the substance passing continuously through the first aperture of the first sensor and through said cavity;providing a second sensor having a waveguide defining a chamber therewithin, said chamber being sized and configured for propagating a microwave signal therethrough, said waveguide having an end forming a short within said chamber, said waveguide having a second aperture extending substantially perpendicular through said waveguide and generally parallel with the end;directing the substance continuously through said second aperture;directing a microwave signal having a frequency in the range of 10-25 GHz through said chamber;detecting the microwave signal directed into said chamber and detecting the microwave signal reflected back from said short;converting the detected microwave signals into a ratio and converting the ratio into a digitized signal for receipt by the processor; anddetermining within the processor a weight of the substance using the dielectric constant measurement and compensating the weight with said digitized signal of the ratio corresponding to the amount of free water contained within the substance.