NASA 1999 SBIR Phase I


PROPOSAL NUMBER 99-1 01.07-3372 (Chron: 991803 )

PROJECT TITLE

A Magnetoresistive Sensor-Based Eddy Current Probe


TECHNICAL ABSTRACT (LIMIT 200 WORDS)

The development of an innovative reflection type eddy current probe in which a giant magnetoresistive (GMR)sensor is used as the replacement for the pickup coil is proposed. The GMR sensor would be made of giant magnetoresistive elements connected in a Wheatstone bridge configuration. During a measurement, this new eddy current probe will provide three independent pieces of information. Namely, the phase and magnitude signal of a standard reflective probe plus a dc signal resulting from the instantaneous magnitude of the magnetic flux generated at the sensor by the eddy currents induced in the conductive target by the driver coil. The use of the GMR sensor would make it possible to design a tangential probe whose induced eddy currents would penetrate deeper into conductive specimens during defect measurements. The successful completion of Phase I effort will provide the basis for the development a field demonstrable probe that could be operated over a wide frequency range and aportable handheld eddy current device in Phase II. The use MR sensors as the pickup sensor could result a chippackage containing a driver coil that could lead to the development of smaller, faster, inexpensive eddy currentsensors.


POTENTIAL COMMERCIAL APPLICATIONS

The successful completion of Phase II of this effort will lead to the development of: a) A MR sensor-based eddy current probe that may be used with existing eddy current instruments; b)A simple handheld instrument that uses the dc output of the bridge to measure a conductor thickness. The device would consist of a driver coil, a sinusoidal source and a digital output display; and, c) An eddy current instrument that utilizes the three independent pieces of information for variety of parameter measurements.


NAME AND ADDRESS OF PRINCIPAL INVESTIGATOR (Name, Organization Name, Mail Address,

City/State/Zip)

F.E. Levert

KEMP, Inc.

1725 Magnolia Ave.

Knoxville , TN 37917 - 7827


NAME AND ADDRESS OF OFFEROR (Firm Name, Mail Address, City/State/Zip)

KEMP, Inc.

1725 East Magnolia Avenue

Knoxville , TN 37917 - 7827