Gary L Fletcher

US Patent:

47651792, Aug 23, 1988

Filed:

Mar 6, 1987

Appl. No.:

7/022973

Inventors:

Milton E. Fuller - Reno NV
Gary S. Fletcher - Carmichael CA

Assignee:

Solid State Farms, Inc. - Reno NV

International Classification:

G01N 2902

US Classification:

73 53

Abstract:

An apparatus and method for measuring the concentration of a chemical substance in a test sample based on a technique of waveform distortion analysis is disclosed. The apparatus includes a waveform generator that generates a periodic electromagnetic signal having a plurality of frequencies simultaneously present. Preferably the signal has a fundamental frequency and simultaneously present harmonic frequencies which shape the waveform. The shaped periodic signal is transmitted through the test sample by a probe assembly which also receives the transmitted signal from the test sample. Propagation of the shaped signal through the test sample results in a change in the waveform shape or distortion by the chemical, and a detector circuit is provided that quantifies the change in shape of the signal to determine the concentration of the chemical in the test sample. The harmonics producing the waveform shape and the fundamental frequency of the signal are both selected so that the change in shape of the signal is particularly responsive to the presence of a selected chemical substance. The magnitude of the distortion or change in shape of the signal can be directly correlated to the concentration of the selected chemical substance.

US Patent:

46794263, Jul 14, 1987

Filed:

Sep 9, 1985

Appl. No.:

6/774150

Inventors:

Milton E. Fuller - Reno NV
Gary S. Fletcher - Citrus Heights CA

International Classification:

G01N 2902

US Classification:

73 53

Abstract:

An apparatus and method for measuring the concentration of a chemical substance in a test sample based on a technique of waveform distortion analysis is disclosed. The apparatus includes a waveform generator that generates a periodic signal, an antenna probe that transmits the signal into the test sample and receives from the test sample a corresponding periodic signal, the waveform of which has been distorted or otherwise transformed by the chemical, and a detector circuit that quantifies the transformation of the signal to determine the concentration of the chemical in the test sample. The waveform shape and frequency are selected so that the transformation is particularly responsive to the presence of a selected chemical substance, so that the magnitude of the distortion or transformation of the signal is directly related to the concentration of the selected chemical substance.