James R Starr

US Patent:

52283399, Jul 20, 1993

Filed:

Apr 28, 1992

Appl. No.:

7/877260

Inventors:

Joseph W. Maresca - Sunnyvale CA
James W. Starr - Bound Brook NJ
Christopher P. Wilson - La Honda CA

International Classification:

G01F 2328

US Classification:

73290V

Abstract:

An apparatus for measuring liquid levels and leak rates in a storage tank, using an acoustic transducer and a quasi-static reference device that positions an acoustic target within a predetermined distance range below the surface of the liquid.

US Patent:

51899043, Mar 2, 1993

Filed:

Jan 3, 1992

Appl. No.:

7/816800

Inventors:

Joseph W. Maresca - Sunnyvale CA
James W. Starr - Bound Brook NJ
Christopher P. Wilson - La Honda CA

Assignee:

Vista Research, Inc. - Mountain View CA

International Classification:

G01M 326

US Classification:

73 405R

Abstract:

The piston displacement apparatus and method for detection of leaks in pressurized pipelines disclosed herein measures volume changes at different pressures to determine thermally compensated leak rates. The apparatus uses a piston displacement apparatus to precisely determine volume changes.

US Patent:

54150337, May 16, 1995

Filed:

Dec 17, 1993

Appl. No.:

8/170092

Inventors:

Joseph W. Maresca - Sunnyvale CA
James W. Starr - Bound Brook NJ
Christopher Wilson - La Honda CA
Richard F. Wise - Manville NJ

Assignee:

Vista Research, Inc. - Mountain View CA

International Classification:

G01M 328

US Classification:

73 405R

Abstract:

An apparatus for detection of leaks in pressurized pipelines which utilizes a large pressure vessel and a small measurement vessel. The measurement vessel magnifies level changes during leak detection tests. The apparatus is connected to a pipeline through the measurement vessel. The entire system can be filled with liquid from the pipeline by opening a valve between the measurement and pressure vessels. Leak detection tests are conducted by measuring changes in volume with the measurement vessel over time while the pressure over the liquid in the pressure vessel and measurement vessel is maintained approximately constant. During tests, liquid communication between the measurement vessel and pressure vessel is prevented by closing the valve between them, but vapor communication between the vessels is permitted.

US Patent:

59489693, Sep 7, 1999

Filed:

Oct 20, 1997

Appl. No.:

8/954002

Inventors:

Michael R. Fierro - Mountain View CA
Joseph W. Maresca - Mountain View CA
James W. Starr - Mountain View CA

Assignee:

Vista Research, Inc. - Mountain View CA

International Classification:

G01M 304
G01M 308

US Classification:

73 405R

Abstract:

A method and improved apparatus for detecting leaks in pressurized pipeline systems, which compensate for the thermally induced volume changes of the liquid in the line during a test that are produced by both the nonlinear changes in the mean temperature of the liquid and the pressure-induced perturbations of the temperature of the liquid.

US Patent:

53412559, Aug 23, 1994

Filed:

Oct 12, 1993

Appl. No.:

8/134485

Inventors:

James A. Starr - San Jose CA
Norman R. Sneddon - Aptos CA

Assignee:

Seagate Technology, Inc. - Scotts Valley CA

International Classification:

G11B 5596

US Classification:

360 7708

Abstract:

A computer disc drive includes a disc with circumferentially arranged tracks, a number of sectors on each track, with each sector including positional and data fields. The disc drive also includes a servo system with a magnetic head, arm, motor, and servo signal processor. One track of the disc drive includes a number of sectors, with each of the sectors including a positional field. A second track of the disc drive includes a number of sectors, with each of the sectors including a positional field. The positional fields of the second track are in a phase variant relationship, or staggered configuration, with the positional fields of the first track. Thus, the magnetic head reading from the first track or the second track is assured of producing a coherent signal with positional information that is sufficient for the servo system to process, despite interfering magnetic patterns between the two tracks. The resulting variably coherent signal with positional information allows the servo system to reposition the arm to a desired position.

US Patent:

53754557, Dec 27, 1994

Filed:

Jul 26, 1993

Appl. No.:

8/097457

Inventors:

Joseph W. Maresca - Sunnyvale CA
James W. Starr - Bound Brook NJ
Christopher Wilson - La Honda CA

Assignee:

Vista Research, Inc. - Mountain View CA

International Classification:

G01M 326

US Classification:

73 405R

Abstract:

A method for measuring thermally corrected leak rates in a pressurized pipeline system. The pipeline system is pressurized to at least two different pressures, and changes of volume of product required to maintain approximately constant pressure are measurized at each pressure. A temperature-compensated volume rate is computed.

US Patent:

51272660, Jul 7, 1992

Filed:

Sep 19, 1990

Appl. No.:

7/585713

Inventors:

Joseph W. Maresca - Sunnyvale CA
James W. Starr - Bound Brook NJ
Christopher P. Wilson - La Honda CA

Assignee:

Vista Research, Inc. - Mountain View CA

International Classification:

G01F 2328

US Classification:

73290V

Abstract:

Methods for measuring liquid levels and leak rates in a storage tank, using an acoustic transducer and a quasi-static reference device that positions an acoustic target within a predetermined distance range below the surface of the liquid. A method for measuring the height of the surface of a liquid, i. e. , liquid level. In a tank comprising the steps of (a) positioning the emitting and receiving acoustic transducers below the surface of the liquid, (b) positioning a plurality of fiducials separated by known distances such that at least two of the fiducials lie below the surface of the liquid, (c) emitting acoustic signals, (d) receiving and measuring the travel times for the reflections of the acoustic signals from the liquid surface and the fiducials, (e) estimating the speed of sound in the liquid using the travel times for the acoustic signals in the liquid between at least two of the fiducials, and (f) calculating the height of the liquid surface by multiplying the speed of sound in the liquid by the travel time from the liquid surface to a known height above the bottom of the liquid, and adding the known height to the product of the speed of sound and travel time.

US Patent:

52633713, Nov 23, 1993

Filed:

Jan 30, 1992

Appl. No.:

7/830229

Inventors:

Joseph W. Maresca - Sunnyvale CA
James W. Starr - Bound Brook NJ
Christopher P. Wilson - La Honda CA

International Classification:

G01F 2328

US Classification:

73290V

Abstract:

A method for measuring the temperature-compensated change in the height of a surface of a liquid. The method positions an acoustic signal transducer for emitting and receiving acoustic signals below the surface of the liquid, positions a quasi-static reference device with a fiducial such that the fiducial lies within a predetermined range below the surface of the liquid, and positions one or more fiducials below the surface of the liquid to establish points separated by known distances. The transducer emits acoustic signals, and receives their reflections. The travel times of the reflections from the liquid surface and the fiducials are used to calculate changes in travel times during the measurement period, to estimate the speed of sound in the liquid, to correct for temperature-induced changes in the travel times, and to obtain a temperature-compensated change in travel time to the liquid surface. The temperature-compensated change in the height of the surface of the liquid during the measurement period is calculated using the product of the estimate of the speed of sound in the liquid and the temperature-compensated change in travel time to the liquid surface. The presence of a leak in a storage tank may be detected by converting the temperature-compensated change in the height of the surface of the liquid to temperature-compensated volume change using the known shape of the tank and liquid height, and then comparing the temperature-compensated volume change to a threshold value to determine whether the tank is leaking.