NDT Methods
Comprehensive guide to all major Non-Destructive Testing methods — ultrasonic testing (UT and PAUT), radiographic testing (RT), magnetic particle testing (MT), liquid penetrant testing (PT), eddy current testing (ET) and visual testing (VT) — with applications, techniques, codes and standards. Learn how each method detects surface and volumetric flaws and when to use it, then explore method-specific training and inspection services. See ultrasonic testing, radiographic testing and NDT training.
Method selection starts with the discontinuity or condition you need to detect, the material, the geometry and the available access. No single method answers every inspection question.
Surface and internal examination
Visual examination establishes accessible surface condition and helps direct further work. Penetrant testing can reveal suitable surface-breaking discontinuities on nonporous materials; magnetic-particle testing is limited to ferromagnetic materials. Surface preparation and access affect both.
Ultrasonic and radiographic techniques can examine internal conditions, but orientation, geometry, resolution and coverage differ. Eddy-current techniques depend on electrical conductivity and a suitable setup. A method name does not define the achievable detection capability for a particular part.
Write the technique and reporting requirements
Record what must be covered, what access is available and what limitations will remain. Agree the applicable procedure, reference checks, personnel requirements and acceptance criteria before the examination begins.
For example, a thickness survey intended to trend corrosion needs repeatable measurement locations. A weld examination intended to detect planar discontinuities needs a technique and coverage appropriate to that objective. The same instrument cannot make those scopes interchangeable.