Industrial testing guide
Time-of-Flight Diffraction (TOFD)
A high-level explanation of diffraction-based ultrasonic flaw sizing concepts.
Safety boundary: this page is conceptual. It does not provide ionizing-radiation source handling, pressure-test procedures, hazardous chemical recipes, energized test instructions, machine settings or robot operation.
What this topic covers
A high-level explanation of diffraction-based ultrasonic flaw sizing concepts.
Core testing ideas
TOFD uses diffracted sound from flaw tips as part of defect characterization.
It is often used with other ultrasonic methods because each technique has strengths and limitations.
Detailed setups and acceptance decisions are specialist work.
Measurement and method limits
Method capability depends on material, geometry, access, surface condition, calibration and operator competence.
Evidence and traceability
Indications require interpretation and comparison with approved acceptance requirements.
Using the result
Hazardous radiation, pressure, chemicals and machine-operation details are intentionally excluded.