Stuart A Nelson

US Patent:

6691563, Feb 17, 2004

Filed:

Apr 11, 2001

Appl. No.:

09/829966

Inventors:

Samir Trabelsi - Athens GA
Stuart O. Nelson - Athens GA
Andrzej W. Kraszewski - Athens GA

Assignee:

The United States of America as represented by the Department of Agriculture - Washington DC

International Classification:

G01N 2556

US Classification:

73 73, 324640

Abstract:

A universal calibration method and apparatus for nondestructive real time determination of moisture content in particulate or granular materials by radio-frequency sensors is described which is bulk-density and material-independent and remains valid across instruments of different designs.

US Patent:

8629681, Jan 14, 2014

Filed:

May 18, 2010

Appl. No.:

12/782079

Inventors:

Samir Trabelsi - Athens GA, US
Stuart O. Nelson - Athens GA, US

Assignee:

The United States of America, as represented by the Secretary of Agriculture - Washington DC

International Classification:

G01R 27/04

US Classification:

324639, 324637, 324640

Abstract:

A microwave sensor and algorithm for instantaneous and nondestructive determination of bulk density and moisture content in granular or particulate materials at a single microwave frequency, especially agricultural commodities, which uses an inexpensive microwave circuit for determining the real and imaginary parts of relative complex permittivity using an algorithm for phase correction.

US Patent:

61475033, Nov 14, 2000

Filed:

May 8, 1998

Appl. No.:

9/074394

Inventors:

Stuart O. Nelson - Athens GA
Samir Trabelsi - Athens GA
Andrzej W. Kraszewski - Athens GA

Assignee:

The United States of America as represented by the Secretary of
Agriculture - Washington DC

International Classification:

G01N 2204

US Classification:

324637

Abstract:

A method for simultaneously and independently measuring moisture content and bulk density of particulate materials using radio-frequency measurements allowing for on-line, real-time monitoring and control. Moisture and density are determined by measurements of complex permittivities. This method is based on the use of the dielectric properties of the materials for density and water content determination.

US Patent:

55549357, Sep 10, 1996

Filed:

Apr 3, 1995

Appl. No.:

8/416405

Inventors:

Andrzej W. Kraszewski - Athens GA
Stuart O. Nelson - Athens GA

Assignee:

The United States of America, as represented by the Secretary of
Agriculture - Washington DC

International Classification:

G01R 2704

US Classification:

324637

Abstract:

A method for nondestructively determining the mass of arbitrarily shaped dielectric objects is disclosed. The object is inserted into a microwave resonant cavity coupled to a microwave radiation source and a measuring circuit. Measurements of shift of resonant frequency and change in the transmission coefficient due to the presence of the object in the cavity are made. The mass is determined from using this information. The process is particularly useful for determining the mass of articles that are too hot or too cold or too fragile to handle and for articles that are irregular or variable in shape.

US Patent:

52183092, Jun 8, 1993

Filed:

Jun 25, 1990

Appl. No.:

7/542548

Inventors:

Stuart O. Nelson - Athens GA
Richard G. Leffler - Athens GA
Kurt C. Lawrence - Snellville GA

Assignee:

The United States of America as represented by the Secretary of
Agriculture - Washington DC

International Classification:

G01R 2726

US Classification:

324664

Abstract:

A method for the nondestructive measurement of the moisture content of single grain kernels, seeds, nuts, or fruits which is independent of their weight, thickness, and projected area. At least two independent parameters of complex electrical impedance or admittance of a single grain kernel, seed, nut, or fruit are measured at two different frequencies and the moisture content is calculated therefrom.

US Patent:

50399470, Aug 13, 1991

Filed:

Jun 1, 1990

Appl. No.:

7/532294

Inventors:

Andrzej W. Kraszewski - Athens GA
Stuart O. Nelson - Athens GA

Assignee:

The United States of America as represented by the Secretary of
Agriculture - Washington DC

International Classification:

G01N 2204

US Classification:

324634

Abstract:

A process for nondestructively determining the moisture content of single articles such as single grain kernels, seeds, nuts, fruits, or other biological or agricultural products. The article is inserted into a microwave resonant cavity coupled to a microwave radiation source and a measuring circuit. Measurements of the energy dissipated in the sample and the shift in frequency (or wavelength) due to the presence of the article in the cavity are made at each of two orientations differing by about 90 degrees with respect to the maximum electric field vector. The moisture content is subsequently determined from the ratio of the averaged values of the energy dissipated to the shift in frequency. The process is particularly useful for determining the moisture content of articles of irregular or variable shape.