Articles & Papers
In this area, we hope to provide some useful and educational material that covers the topics of NDT as well as Eddy Currents and Eddy Current NDT.
Weld Inspection using Eddy Current Technology
ETher NDE, AZO Materials 2012
The weld probe offers a good alternative to MPI inspection as there is no need to remove the coating. It is highly suited for rope access inspectors. The probe is relatively convenient to use so it find applications in axle inspection. Training courses with operator certification, national standards and acceptance by certifying authorities imply that the weld probe becomes a recognised solution.
Buried Corrosion Detection in Multi-layer Airframe Structures using Pulsed Eddy Current
Christne Murner & John Hansen
17th WCNDT 2008
Substantial enhancements in Pulsed Eddy Current instrumentation and array probes provide a unique capability for the detection and imaging of sub-layer corrosion. The use of giant magnetoresistive (GMR) elements in an inductive array provides increased depth of sensitivity over conventional eddy-current sensing coils. This paper provides an overview of newly developed instrumentation, which provides a portable, battery-operated platform for multi-layer corrosion detection in flight line or repair facilities.
Automatic Differential Lift-Off Compensation (AD-LOC) method in Pulsed Eddy Current Inspection
Joanna X Qiao, John Hansen & Ian Mayes
17th WCNDT 2008
In the state of art Pulse Eddy Current inspection application, we present a novel method of Automatic Differential Lift-Off Compensation (AD-LOC). The lift-off key features were defined and extracted by the discovery of a strong relationship between the differential peak value of the sensed PEC signal and the lift-off distance. The corresponding compensation formula was then created. A practical implementation scheme was proposed based on the described method.
New Object Definitions for DICONDE
M. Jobst, J. Hansen, P. Howard, L. Arrowood
4th European-American workshop on Reliability of NDE
In 2004, ASTM published the DICONDE (Digital Imaging and Communication in NDE) standard practice for the storage and communication of digital nondestructive evaluation (NDE) results. The current DICONDE practice (ASTM E2339-08) addresses only issues that apply to all NDE modalities. We will discuss our methodology for developing new Information Object Definitions for those NDT imaging modalities that have needs that are not currently addressed by the ASTM 2339-08 standard. We describe our definitions for ultrasound, digital radiography and computed tomography based on metadata in the ACR-NEMA DICOM standard with adaptations for industrial applications.
The Changing Image of Eddy Current
Eddy current inspection can offer significant, practical advantages over other inspection techniques in certain situations. Unlike ultrasonic inspection, there is no need for any couplant; it can be used on wet surfaces and there is no need for consumables, unlike dye penetrant, wet film radiography and magnetic particle inspection (MPI) techniques.
ASNT Back to Basics Series: “Using Eddy Current to solve industrial problems”
J. Hansen & R. Peoples
This article on conventional eddy current testing, which relies for its basic principle on the material properties of electrical conductivity, magnetic permeability and dimensions.