Glossary
Glossary
Definitions of terms commonly used in non-destructive testing (NDT), periodic inspection and certification.
- Non-Destructive Testing(NDT)
- The general term for inspection methods that detect surface and internal defects (cracks, voids, weld flaws) without causing permanent damage to the material or product.
- Radiographic Testing(RT)
- A non-destructive method that images the internal structure of a material using X-ray or gamma radiation to identify volumetric defects (porosity, slag, lack of penetration).
- Ultrasonic Testing(UT)
- A non-destructive method that determines internal defects and thickness by measuring the reflection of high-frequency sound waves within a material.
- Phased Array Ultrasonic Testing(PAUT)
- An advanced ultrasonic technique that electronically steers and focuses the sound beam with a multi-element probe, providing high-resolution, imaged and fast inspection.
- Time-of-Flight Diffraction(TOFD)
- An ultrasonic technique that sizes weld flaws with high accuracy by measuring the arrival time of ultrasonic waves diffracted from defect tips.
- Magnetic Particle Testing(MT)
- A non-destructive method that magnetizes ferromagnetic materials and reveals surface and near-surface cracks using magnetic particles applied to the surface.
- Liquid Penetrant Testing(PT)
- A non-destructive surface method that reveals cracks and pores using a colored or fluorescent liquid that penetrates surface-breaking defects.
- Visual Testing(VT)
- The fundamental non-destructive method that evaluates surface defects, geometric conformity and weld bead quality by eye or with optical aids.
- Destructive Testing(DT)
- Laboratory testing that determines a material's mechanical and metallurgical properties through tensile, bend, impact and hardness tests, consuming the specimen.
- Periodic Inspection
- Inspection of work equipment (pressure vessels, lifting equipment, installations) at defined intervals per regulations and standards. In Türkiye it is mandatory under the Regulation on Health and Safety Conditions in the Use of Work Equipment.
- Inspection Body Accreditation(ISO/IEC 17020)
- The international standard defining the competence and impartiality of bodies performing inspection. A type-A inspection body meets its independence requirements.
- Personnel Certification Accreditation(ISO/IEC 17024)
- The international standard defining the competence of bodies certifying persons. NDT personnel certification is conducted within this framework.
- Laboratory Accreditation(ISO/IEC 17025)
- The international standard defining the technical competence of testing and calibration laboratories, assuring the validity of accredited test results.
- NDT Personnel Certification Standard(EN ISO 9712)
- The international standard defining training, examination and certification requirements for NDT personnel by method and level (Level 1-2-3).
- Rope Access
- A method providing safe access to high or hard-to-reach structures using rope systems instead of scaffolding, making inspection and maintenance faster and more economical.
- Positive Material Identification(PMI)
- A method that non-destructively verifies the alloy composition of a material (usually by X-ray fluorescence) to confirm conformance to specification.
Frequently Asked Questions
NDT is the general term for inspection methods that detect surface and internal defects without permanently damaging the material or product. The main methods are radiography (RT), ultrasonic (UT), magnetic particle (MT), penetrant (PT) and visual testing (VT).