TITLE

Deep flaw detection with giant magnetoresistive (GMR) based self-nulling probe

AUTHOR(S)
Wincheski, Buzz; Namkung, Min
PUB. DATE
May 2000
SOURCE
AIP Conference Proceedings;2000, Vol. 509 Issue 1, p465
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Giant magneto-resistive sensors provide a high sensitivity to low frequency magnetic fields. This, combined with an inherent small size, low cost, and low power consumption, make GMR sensors a good candidate for low frequency eddy current probe development. Previous research has shown that the incorporation of a GMR sensor in the NASA LaRC developed Self-Nulling Eddy Current Probe greatly enhances the low frequency detection capabilities of the device. Experimental results have shown the detection of a 1.4 cm long notch under up to 9 mm of unflawed aluminum. A limiting factor in this work appeared to be the increased background level with decreasing frequency. In order to improve the signal-to-noise ratio several techniques have been incorporated to reduce the background level and increase the signal-to-noise ratio. The incorporation of a gradiometric sensor, active feedback, and improved shielding have led to an enhanced detectability. In addition, image processing techniques have been explored to filter out background variations from the processed data. Finite element modeling results for the newly designed probe are presented along with experimental data for the detection of EDM notches and fatigue cracks in multi-layered aluminum alloy samples. © 2000 American Institute of Physics.
ACCESSION #
6029096

 

Related Articles

  • Noise characteristics of 100 nm scale GaAs/AlxGa1-xAs scanning Hall probes. Hicks, C. W.; Luan, L.; Moler, K. A.; Zeldov, E.; Shtrikman, H. // Applied Physics Letters;3/26/2007, Vol. 90 Issue 13, p1 

    The authors have fabricated and characterized GaAs/AlxGa1-xAs two-dimensional electron gas scanning Hall probes for imaging perpendicular magnetic fields at surfaces. The Hall crosses range from 85×85 to 1000×1000 nm2. They study low-frequency noise in these probes, especially random...

  • Simple and efficient method for carbon nanotube attachment to scanning probes and other substrates. Hall, A.; Matthews, W. G.; Superfine, R.; Falvo, M. R.; Washburn, S. // Applied Physics Letters;4/14/2003, Vol. 82 Issue 15, p2506 

    We present a fast, high yield, low cost method for the production of scanning probes with aligned carbon nanotubes protruding from the ends. The procedure is described and images of undercut films are used to demonstrate the improved probe quality for topography measurements. A magnetophoretic...

  • Build a 125-MHz logic probe. Yost, Paul // Popular Electronics;Feb94, Vol. 11 Issue 2, p57 

    Focuses on high-speed digital-logic probe. Theory of operation; Functions; Features; Construction; Testing; Steps in locating and correcting failures.

  • Users measure workpiece dimension and form.  // Modern Machine Shop;Feb96, Vol. 68 Issue 9, p276 

    Features Browne & Sharpe Manufacturing Co.'s MiniTRAX probes. Applications; Specifications; Capabilities.

  • A capacitive probe array for measurements of ionization growth. Choi, P.; Favre, M. // Review of Scientific Instruments;Jul1994, Vol. 65 Issue 7, p2281 

    The design and construction of a novel capacitive probe array to directly measure the ionization growth in high-voltage discharges is presented. By optimizing the design geometry, the probe output is made to be dependent only on the variation of charge development or potential changes at the...

  • A self-assembled microlensing rotational probe. Brody, James P.; Quake, Stephen R. // Applied Physics Letters;1/4/1999, Vol. 74 Issue 1, p144 

    Studies a self-assembled microlensing rotational probe. Attachment of a small fluorescent polystyrene microsphere to a larger polystyrene microsphere; Measurement of the rotational diffusion constant.

  • To probe or not to probe. Marchito, Edward // Modern Machine Shop;Apr95, Vol. 67 Issue 11, p52 

    Answers questions concerning touch probes in machine shops. Usage; Most common probing applications; Cost benefits; Ways in which fixturing is important to probing; Capability of machine tools to incorporate probing with the simple addition of software.

  • CNC tech talk. Lynch, Mike // Modern Machine Shop;Dec93, Vol. 66 Issue 7, p136 

    Presents a sample probing program written in Custom Macro. Program's need for manual intervention.

  • CNC commands related to probing. Lynch, Mike // Modern Machine Shop;Jan95, Vol. 67 Issue 8, p148 

    Discusses consecutive number control commands needed to program probes. Probe on/probe off; Spindle orient (M19); Disable feed rate override; Skip cutting command (G31); Attainment of machine position; Stylus radius and calibration variables.

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics