Trw Limited

James L Schmidt

Jerold L Jacoby

Pravin G Bhuta

Garrett D Shaw

An instrument for determining the stress in the wall of a borehole by recording successively on the same holographic recording medium two holograms of a selected surface region of the wall, and, in the interval between the two recordings, forming a stress relief in the wall in stress relieving relation to the surface region to produce on the recording medium a double exposure hologram. This hologram contains holographic information which represents the stress in the wall in the vicinity of the surface region and may be converted to data defining the magnitude and direction of the stress.

Growing community of inventors

Redondo Beach, CA, United States of America

James L Schmidt