Mechanical Technology Incorporated

Gregory Hull-Allen

Richard A Dorman

Curtis D Kissinger

Leo Hoogenboom

Samuel Fallek

A fiber optic sensor probe system comprises an electromechanical arrangement system which enables a fiber optic probe to lock onto a null point relative to a target which null point represents an in focus condition for the probe relative to the target. A servomechanism feedback circuit maintains the probe in an in focus condition relative to the target if the target moves. A dithering motion is provided to the probe such that, when the electrical output of the probe has a frequency component which is the same frequency as that of the dither, an out of focus condition of the probe relative to the target exists and the servomechanism feedback system operates to correct it. A monochromatic light source is used to eliminate the problem of different spectral components of light having slightly different focal lengths. A second dither or oscillation of the servomechanism's motor drive voltage causes the motor to oscillate and thus enables it to avoid becoming stuck by static friction, therefore enabling the system to achieve its proper null point. Finally, the geometry of the probe is such that the lens face is not parallel to the target, so that flat regions in the area of the null response point of the output curve of the probe which might cause the probe to hunt excessively for the null point are eliminated.

Fiber optic sensor probe

A method of determining the displacement of a fiber optic sensor from a target in which a first lens is spaced from the target at a first distance an a second lens is spaced from said target at a second distance which provides the greatest intensity response at said first distance and thereafter spacing said first lens from said second lens to provide symmetrical slope values of response.

Optical configuration of fiber optic sensor for symmetric dynamic

A displacement measuring instrument for measuring the displacement of a target including in combination a fiber optic lens assembly including means for maintaining said assembly in space relation with said target, dither means for vibrating said assembly toward and away from said target about the lens null along the axis of said assembly, first electronic means for providing a first output voltage proportional to displacement of said assembly from said target, second electronic means cancelling that portion of said first output voltage resulting from displacement due to said dither means and providing a second voltage resulting from displacement due to means other than said dither means, servo means receiving said second output voltage and moving said assembly with respect to said target to null said second output voltage and measurement means measuring the movement of said servo means.

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Schenectady, NY, United States of America

Gregory Hull-Allen