NDT methods can generally be classified into two categories: conventional and advanced. Each method has its own characteristic advantages and limitations. More information on each test can be found in their respective Integripedia definitions.
Conventional NDT Techniques
Conventional methods are techniques that have matured over the course of decades and in this time, have become well-documented in codes, standards, and best practices. The setup and procedure of a conventional technique is typically simpler in comparison to advanced methods.
- Acoustic Emission Testing(AET)
- Infrared Testing(IR)
- Leak Testing (LT)
- Liquid Penetrant Testing(PT)
- Electromagnetic Testing (ET)
- Magnetic Particle Testing(MPT)
- Radiographic Testing(RT)
- Film Radiography (FR)
- Ultrasonic Testing(UT)
- Vibration Analysis (VA)
- Visual Inspection(VI)
Advanced NDT Techniques
Advanced methods tend to be less understood as they progress as emerging technologies, e.g. uncertain advantages or limitations, lack of technician qualification criteria, or little to no industry codification. Generally, the setup, procedure, and data interpretation of advanced methods are more complicated and can require specialized understanding and experience from a properly trained technician.
Furthermore, some methods can be further broken down into conventional and advanced techniques. Take two forms of ultrasonic testing, for example, straight beam ultrasonic testing (UT) is a conventional technique used in simple applications whereas phased array ultrasonic testing (PAUT) is an advanced UT technique. As advanced techniques mature, new and more advanced versions of each emerge to start a new cycle of technical understanding and technician training.
Electromagnetic Testing (ET)
- Alternating Current Field Measurement
- Eddy Current Testing (ECT)
- Magnetic Flux Leakage(MFL)
Laser Testing Methods (LM)
- Holographic Testing
- Laser Profilometry
- Laser Shearography
- Computed Radiography (CR)
- Computed Tomography (CT)
- Digital Radiography (DR)
- Angle Beam
- Automated Ultrasonic Backscatter Technique (AUBT)
- Electromagnetic Acoustic Transducer (EMAT)
- Immersion Testing
- Internal Rotary Inspection System (IRIS)
- Long Range Ultrasonic Testing (LRUT)
- Phased Array Ultrasonic Testing (PAUT)
- Time-of-Flight-Diffraction (TOFD)
Overall, NDT offers many advantages compared to destructive testing. The testing equipment is often portable and can be performed numerous times on a single component. The component itself can be thoroughly evaluated externally and internally for harmful flaws. The disadvantage is that the results are often qualitative and may be repeated and interpreted differently by various inspectors.