Gary Douglas Hendrix, 68PO Box 1307, Castroville, TX 78009

4890496, Jan 2, 1990

Sep 7, 1988

7/241504

Anmol S. Birring - San Antonio TX
David G. Alcazar - San Antonio TX
Gary J. Hendrix - San Antonio TX
John J. Hanley - San Antonio TX

Electric Power Research Institute - Palo Alto CA

G01N 2904

73597

A method for detecting hydrogen attack by ultrasound wave velocity measurements in which ultrasound waves (e. g. longitudinal, shear, or creeping) are transmitted from one transducer to another transducer along a fixed path through a steel body such as pipe. The velocity of the ultrasound wave is determined with an accuracy of 0. 1 percent from the fixed path length and the time for a wave to travel from one transducer to the other transducer. A decrease in velocity by more than two percent indicates hydrogen attack. In one embodiment, either refracted longitudinal or refracted shear waves are transmitted, and the velocities thereof are determined. In another embodiment, a creeping wave is transmitted from one transducer to the other transducer with the creeping wave including a surface wave and a subsurface wave. Travel time of the subsurface wave is measured and used with the known fixed path length in determining velocity. In the third embodiment ultrasonic waves are transmitted into the material and the backscattered ultrasound is measured.

4711120, Dec 8, 1987

Oct 6, 1986

6/915382

Hegeon Kwun - San Antonio TX
Anmol S. Birring - San Antonio TX
Gurvinder P. Singh - San Antonio TX
Gary J. Hendrix - San Antonio TX
David G. Alcazar - San Antonio TX

Association of American Railroads - Washington DC

G01M 1500

73119R

A method of monitoring the cylinder wall wear using ultrasonic phase comparison techniques is disclosed. The method comprises the steps of introducing ultrasonic waves in a cylinder wall so that the waves travel through the cylinder wall. A change in the traveling time of the ultrasonic waves traveling through the cylinder wall due to cylinder wall wear is determined. The amount of wear of the cylinder wall is calculated by multiplying the velocity of the ultrasonic waves in the cylinder wall by the traveling time change due to cylinder wall wear. The traveling time change due to cylinder wall wear is obtained by determining the actual change in travel time by a phase comparison of the traveling ultrasonic waves and adjusting the actual change in travel time to compensate for any change due to temperature variation of the cylinder wall. With this method, small changes in traveling time on the order of 10. sup. -11 second can be determined so that thickness changes due to wear on the order of 5. times. 10. sup.

D357226, Apr 11, 1995

Sep 3, 1993

D/012552

Steven R. Ybanez - San Antonio TX
Gary D. Hendrix - Castroville TX
Williams M. Toner - San Antonio TX
Arthur F. Lopez - San Antonio TX
Richard G. Ybanez - New Braunfels TX

Data Optics Cable - San Antonio TX

D13146

4788708, Nov 29, 1988

Nov 25, 1987

7/125569

Gary Hendrix - San Antonio TX

Tele-Technix, Inc. - San Antonio TX

H04R 2900
H04M 124

379 6

A device for testing performance of telephone headsets. The device performs reception, transmission, reception distortion, transmission distortion, reception limiting, and current consumption testing, as well as allowing these same tests with reverse polarity. The complete headset may be tested, or just the bottom or top units may be tested, as well as auxiliary power packs. The tester is designed to be used with any conventional headset, regardless of variations in the specifications, such as power supply. The tester may be programmed for an automatic testing mode.