William James Bowers

US Patent:

6363773, Apr 2, 2002

Filed:

Apr 18, 2000

Appl. No.:

09/552462

Inventors:

William D. Bowers - Newport Beach CA

Assignee:

Femtometrics - Irvine CA

International Classification:

H03H 925

US Classification:

73 2406, 73 3106, 310313 R, 310313 D

Abstract:

A real time nonvolatile residue (NVR) monitor operates to efficiently detect molecular contamination in a given environment. The present NVR monitor utilizes surface acoustic wave (SAW) resonators in a controlled environment which efficiently promotes deposition of NVR on the sensor surface. The SAW resonators preferably operate at a resonant frequency of approximately 200 MHz-2,000 MHz which enables the NVR monitor to detect molecular contamination on the order of 10 g-cm to 10 g-cm. The NVR monitor utilizes active temperature control of (SAW) resonators to achieve a stable resonant frequency and to thermally separate NVR from a sample fluid contacting the SAW. The temperature control system of the NVR monitor is able to directly heat and cool the SAW resonators utilizing a thermoelectric element to maintain the resonators at a preset temperature in accordance with optimal environmental conditions for separating NVR from the sample fluid. The sample fluid, comprising a carrier fluid and NVR, is furthermore processed to provide conditions, such as pre-cooling and/or pressurization, which enhance condensation of NVR on the sensor surface. Increasing the collection efficiency allows the NVR monitor to operate faster at a desired level of accuracy and provides more quantitative information for trace contaminant analysis.

US Patent:

6378385, Apr 30, 2002

Filed:

Feb 19, 2001

Appl. No.:

09/789500

Inventors:

William D. Bowers - Newport Beach CA

Assignee:

Femtometrics, Inc. - Irvine CA

International Classification:

G01N 2518

US Classification:

7386312

Abstract:

A device samples chemicals adsorbed to a surface by applying a pulse of fluid to desorb the particles adhered to the surface. After the pulse of fluid, the region above the surface is enriched with particles dislodged from the surface. Suction is applied in the region above the surface to collect these dislodged particles, which are then transferred to a chemical detector for detection, identification, and quantification. A pulsed air sampler collects particles adhered to a surface and delivers the particles to a chemical sensor. An outlet ejects a fluid, preferably gas, pulse to dislodge particles from the surface and thereby enrich the density of particles above the surface. An inlet collects the dislodged particles for delivery to the chemical sensor.

US Patent:

7399447, Jul 15, 2008

Filed:

Apr 1, 2004

Appl. No.:

10/815983

Inventors:

William D. Bowers - Newport Beach CA, US
Gregory F. Quinn - Fullerton CA, US

Assignee:

Enigma Science, LLC - Irvine CA

International Classification:

G01N 1/14

US Classification:

422100, 73 6456, 7386301

Abstract:

An active sampler for detecting contaminants in liquids comprises an inlet tube, and outlet tube and a sampling unit positioned between said paths such that the liquid flows along a path from the inlet, through the sampling unit, to the outlet. The sampling unit has a plurality of sampling chambers that are substantially fluidly sealed relative to one another, wherein one of the sampling chambers is selectively positioned in the flow path. The active sampler also comprises an actuator, which relatively moves the sampling unit and the inlet and outlet tubes such that said one sampling chamber is positioned out of the flow path while another of the sampling chambers is positioned in the flow path.

US Patent:

8119065, Feb 21, 2012

Filed:

Jul 15, 2008

Appl. No.:

12/173612

Inventors:

William D. Bowers - Newport Beach CA, US
Gregory F. Quinn - Fullerton CA, US

Assignee:

Enigma Science, LLC - Irvine CA

International Classification:

G01N 1/14

US Classification:

422 681, 73 6456, 7386301

Abstract:

An active sampler for detecting contaminants in liquids comprises an inlet, an outlet and a sampling unit positioned such that the liquid flows along a path from the inlet, through the sampling unit, to the outlet. The sampling unit has a plurality of sampling chambers that are substantially fluidly sealed relative to one another, wherein one of the sampling chambers is selectively positioned in the flow path. The active sampler also comprises an actuator, which relatively moves the sampling unit and the inlet and outlet such that one sampling chamber is positioned out of the flow path while another of the sampling chambers is positioned in the flow path.

US Patent:

59182580, Jun 29, 1999

Filed:

Jul 11, 1996

Appl. No.:

8/678792

Inventors:

William D. Bowers - Newport Beach CA

International Classification:

H03H 925
G01N 2902
G01N 2922

US Classification:

73 2406

Abstract:

A real time nonvolatile residue (NVR) monitor operates to efficiently detect molecular contamination in a given environment. The present NVR monitor utilizes surface acoustic wave (SAW) resonators in a controlled environment which efficiently promotes deposition of NVR on the sensor surface. The SAW resonators preferably operate at a resonant frequency of approximately 200 MHz-2,000 MHz which enables the NVR monitor to detect molecular contamination on the order of 10. sup. -11 g-cm. sup. -2 to 10. sup. -13 g-cm. sup. -2. The NVR monitor utilizes active temperature control of (SAW) resonators to achieve a stable resonant frequency and to thermally separate NVR from a sample fluid contacting the SAW. The temperature control system of the NVR monitor is able to directly heat and cool the SAW resonators utilizing a thermoelectric element to maintain the resonators at a preset temperature in accordance with optimal environmental conditions for separating NVR from the sample fluid. The sample fluid, comprising a carrier fluid and NVR, is furthermore processed to provide conditions, such as pre-cooling and/or pressurization, which enhance condensation of NVR on the sensor surface.

US Patent:

6269703, Aug 7, 2001

Filed:

Sep 11, 1998

Appl. No.:

9/151743

Inventors:

William D. Bowers - Newport Beach CA

Assignee:

Femtometrics, Inc. - Irvine CA

International Classification:

G01N 2518

US Classification:

7386312

Abstract:

A device samples chemicals adsorbed to a surface by applying a pulse of fluid to desorb the particles adhered to the surface. After the pulse of fluid, the region above the surface is enriched with particles dislodged from the surface. Suction is applied in the region above the surface to collect these dislodged particles, which are then transferred to a chemical detector for detection, identification, and quantification. A pulsed air sampler collects particles adhered to a surface and delivers the particles to a chemical sensor. An outlet ejects a fluid, preferably gas, pulse to dislodge particles from the surface and thereby enrich the density of particles above the surface. An inlet collects the dislodged particles for delivery to the chemical sensor.

US Patent:

61229547, Sep 26, 2000

Filed:

Aug 21, 1998

Appl. No.:

9/138043

Inventors:

William D. Bowers - Newport Beach CA

Assignee:

Femtometrics, Inc. - Irvine CA

International Classification:

H03H 925
G01N 2902
G01N 2922

US Classification:

73 2406

Abstract:

A real time nonvolatile residue (NVR) monitor operates to efficiently detect molecular contamination in a given environment. The present NVR monitor utilizes surface acoustic wave (SAW) resonators in a controlled environment which efficiently promotes deposition of NVR on the sensor surface. The SAW resonators preferably operate at a resonant frequency of approximately 200 MHz-2,000 MHz which enables the NVR monitor to detect molecular contamination on the order of 10. sup. -11 g-cm. sup. -2 to 10. sup. -13 g-cm. sup. -2. The NVR monitor utilizes active temperature control of (SAW) resonators to achieve a stable resonant frequency and to thermally separate NVR from a sample fluid contacting the SAW. The temperature control system of the NVR monitor is able to directly heat and cool the SAW resonators utilizing a thermoelectric element to maintain the resonators at a preset temperature in accordance with optimal environmental conditions for separating NVR from the sample fluid. The sample fluid, comprising a carrier fluid and NVR, is furthermore processed to provide conditions, such as pre-cooling and/or pressurization, which enhance condensation of NVR on the sensor surface.

US Patent:

63215888, Nov 27, 2001

Filed:

Sep 11, 1998

Appl. No.:

9/151747

Inventors:

William D. Bowers - Newport Beach CA
Frank Bahrami - Costa Mesa CA
John Tran - Huntington Beach CA

Assignee:

Femtometrics, Inc. - Irvine CA

International Classification:

G01N 2700
G01N 2900
G01N 3106

US Classification:

73 2401

Abstract:

A device for detecting chemical substances includes a plurality of sensors arranged in an array. The sensors are connected to respective oscillator circuits which drive the sensors, and the oscillator circuits are coupled to a power multiplexer which provides the circuits with power according to a timing pattern such that not all of the oscillator circuits are activated at any one time. Preferably, only one oscillator circuit is activated at any given time. This multiplexing arrangement saves power and substantially eliminates cross talk between the oscillator circuits. The oscillator circuits are preferably application specific integrated circuits (ASICs), and the sensors are preferably surface acoustic wave (SAW) devices. In use, the SAW sensors are exposed to a gas, such as air, containing the chemical substance to be detected. Signals from the SAW sensors are analyzed to identify the chemical substance.

Author:

William T. Bowers

ISBN #:

0160488036

Author:

William T. Bowers

ISBN #:

0160488044

Author:

William S. Bowers

ISBN #:

0151010544

Author:

William J. Bowers

ISBN #:

0669856703

Author:

William J. Bowers

ISBN #:

0930350251

Author:

William H. Bowers

ISBN #:

0397520719

Author:

William H. Bowers

ISBN #:

0443032165