Time of Flight Diffraction Level II

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 TOFD Level II banner


Learning Event: eLearning, Self-Paced
Contact Hours: 40
Valid for ASNT Level III recertification: Yes

Pricing:

  • Member: $1,145
  • Nonmember: $1,245
ASNT members receive member pricing on course registration. To receive member pricing, you must join/renew prior to registering for a course.

IMPORTANT: Within 24-48 business hours after registration for this course, learners will receive instructions on how to complete this course on a third-party site. Please email education@asnt.org with any questions.

Course description

 

SECTION 1: BASIC PRINCIPLES OF ULTRASOUND AND ULTRASOUND TESTING

  • NDT 
  • Sound versus Ultrasound 
  • Distance, velocity, cycle, material density 
  • Sine wave, frequency, wavelength 
  • dB system 
  • The shell of an ultrasound instrument, TOFD probes, TOFD wedges 
  • Pulser/receiver, square pulse 
  • Wave propagation, scattering, absorption, energy spreading 
  • Beam, sound field, beam diameter 
  • Through transmission, pulse echo, angle beam, immersion, PAUT 
  • A-Scan 
  • Structure and qualification of a procedure, training, acceptance criteria 
  • Calibration blocks, couplant 
  • Marking on part; probe positioning 
  • Naming files; storing data 
  • Section’s test 

SECTION 2: PRINCIPLES UNDERLYING TOFD 

  • Butt welds 
  • Digital instrument, pulser/receiver, digitizer, filters, gain 
  • Probes, frequency spectrum, signal waveform 
  • Wedges, hard wedges 
  • Scanner, encoder 
  • Huygens’ principal, diffraction 
  • Snell’s law, incident vs. refracted, critical angles 
  • TOFD A-Scan, phase shift, phase difference, averaging 
  • PCS, transit time, depth calculation, height calculation, position uncertainty 
  • Beam spread, beam spread in-wedge, beam spread in-part, frequency spectrum 
  • Lateral wave, backwall, mode-converted backwall 
  • Dead zones, accuracy, resolution 
  • B-Scan, gray scale 
  • Whisker effect, parabolic cursors 
  • Non-parallel and parallel scans 
  • Multiple scans 
  • Influence of frequency on coverage, dead zones 
  • Influence of wedge angle on time scale, coverage 
  • Influence of PCS on dead zones, resolution, coverage 
  • How to optimize the digitizing frequency, filters, averaging, time window, sensitivity, PRF 
  • Calibration of the beam index point, velocity 
  • Scanning speed 
  • Wedge delay calibration, lateral wave straightening, lateral wave removal 
  • Interactive exercises on setups, beam index point and velocity calibration, scanning 
  • Interactive exercises on wedge delay calibration and lateral wave straightening 
  • Section’s test 

SECTION 3: DATA ANALYSIS 

  • B-Scan perspective 
  • Lateral wave, backwall and mode-converted backwall signals 
  • Effect of beam spread on depth and the backwall signal 
  • Indication classification, probe position vs. height, angle vs. height 
  • Geometrical indications, double-V welds, pipes misalignment, different wall thickness 
  • Data quality, calibration, basic analysis, detailed analysis 
  • Signal start, grouping, point-like indications 
  • Height and depth, top-surface breaking, bottom-surface breaking, embedded 
  • Length and position, parabolic shape, elongated and curved 
  • Interactive viewer, top-surface breaking, bottom-surface breaking, embedded 
  • Interactive exercises on setup, beam index calibration, scanning, data analysis 
  • Section’s test 

SECTION 4: REVIEW 

  • Hardware 
  • Scans and views 
  • Theory 
  • Setups 
  • Calibration 
  • Data analysis 
  • The defects 

SECTION 5: FINAL TEST 

  • 50-question final test

*A passing score of 70% on the final exam is required to complete the course and receive a certificate of completion.  Learners will receive three attempts to pass the exam.  If the learner is unable to pass the final exam within the three attempts, the course will need to be repurchased.*

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