May 25, 2024  
2023-2024 College Catalog 
2023-2024 College Catalog [ARCHIVED CATALOG]

NDT 105 - Electromagnetic Testing (ET) Level I

3 Credits, 3 Contact Hours
3 lecture periods 0 lab periods

Provides a basic knowledge of eddy current testing fundamentals sufficient to enable the technician to carry out eddy current testing to established procedures under the supervision of level II or level III personnel. Includes the essentials in electromagnetic theory, test instrumentation and coil design, and basic impedance plane principles. Also includes conductivity, dimensional factors (lift-off and material thickness), permeability, signal-to-noise ratio, frequency, and flaw detection applications.

Prerequisite(s): NDT 100
Button linking to AZ Transfer course equivalency guide  

Course Learning Outcomes
  1. Demonstrate proficient knowledge of electromagnetic testing.
  2. Demonstrate proficient knowledge of the use of eddy current equipment.
  3. Demonstrate proficient knowledge of how to set up and calibrate NDT equipment.
  4. Demonstrate proficient knowledge and basic understanding of Flux leakage.

  1. Introduction to Electromagnetic Testing
    1. Early observation of magnetic attraction
    2. Basic principles of induced currents
    3. Basic principles of flux leakage testing
    4. Personnel qualifications
    5. Personnel certifications 
  2. Eddy Current Theory
    1. Generation of eddy currents
    2. Resistance
    3. Inductive reactance
    4. Impedance
    5. Phase angle
  3. Eddy Current Instrumentation
    1. Eddy current instrument circuits
    2. Internal functions of eddy current instruments
  4. Readout Mechanism
    1. Analog meters
    2. Digital display
  5. Eddy Current Inspection Coils
    1. Surface coil
    2. Encircling coil
    3. Internal coil
    4. Test coil arrangements
    5. Factors affecting choice of sensing elements
  6. Flux Leakage Theory
    1. B and H curve
    2. Lines of force
    3. Law of magnetism
    4. Flux density
    5. Right hand rule
    6. Magnetic properties of materials
  7. Flux Leakage Sensing Elements
    1. Inductive coil sensors
    2. Magnetodiode
    3. Other methods of leakage field detection
  8. Coil Impedance
    1. Test objects
    2. Conductivity
    3. Alloy composition
    4. Hardness
    5. Temperature and residual stress
    6. Conductive coatings
    7. Edge effect
    8. Skin effect
    9. End effect
    10. Permeability
    11. Dimensional factors
    12. Discontinuities
  9. Eddy Current Test Systems and Analysis
    1. Impedance testing systems
    2. Phase analysis
    3. Cathode ray tube method
    4. Modulation analysis

Effective Term:
Fall 2023