Nondestructive testing or non-destructive testing (NDT) is a wide group of analysis techniques used in science and technology industry to evaluate the properties of a material, component or system without causing damage. The terms nondestructive examination (NDE), nondestructive inspection (NDI), and nondestructive evaluation (NDE) are also commonly used to describe this technology. Because NDT does not permanently alter the article being inspected, it is a highly valuable technique that can save both money and time in product evaluation, troubleshooting, and research. The six most frequently used NDT methods are eddy-current, magnetic-particle, liquid penetrant, radiographic, ultrasonic, and visual testing. NDT is commonly used in forensic engineering, mechanical engineering, petroleum engineering, electrical engineering, civil engineering, systems engineering, aeronautical engineering, medicine, and art. Innovations in the field of nondestructive testing have had a profound impact on medical imaging, including on echocardiography, medical ultrasonography, and digital radiography.
Various national and international trade associations exist to promote the industry, knowledge about non-destructive testing, and to develop standard methods and training. These include the American Society for Nondestructive Testing, the Non-Destructive Testing Management Association, the International Committee for Non-Destructive Testing, the European Federation for Non-Destructive Testing and the British Institute of Non-Destructive Testing.
Methods and techniques
NDT is divided into various methods of nondestructive testing, each based on a particular scientific principle. These methods may be further subdivided into various techniques. The various methods and techniques, due to their particular natures, may lend themselves especially well to certain applications and be of little or no value at all in other applications. Therefore, choosing the right method and technique is an important part of the performance of NDT.
- Acoustic emission testing (AE or AT)
- Blue etch anodize (BEA)
- Dye penetrant inspection or liquid penetrant testing (PT or LPI)
- Electromagnetic testing (ET) or electromagnetic inspection (commonly known as "EMI")
- Ellipsometry
- Endoscope inspection
- Guided wave testing (GWT)
- Hardness testing
- Impulse excitation technique (IET)
- Microwave imaging
- Terahertz nondestructive evaluation (THz)
- Infrared and thermal testing (IR)
- Laser testing
- Leak testing (LT) or Leak detection
- Magnetic resonance imaging (MRI) and NMR spectroscopy
- Metallographic replicas[13][14]
- Spectroscopy
- Optical microscopy
- Positive material identification (PMI)
- Radiographic testing (RT) (see also Industrial radiography and Radiography)
- Resonant inspection
- Scanning electron microscopy
- Surface temper etch (Nital Etch)
- Ultrasonic testing (UT)
- Thickness measurement
- Vibration analysis
- Visual inspection (VT)
- Weight and load testing of structures
- Corroscan/C-scan
- 3D computed tomography
- Heat Exchanger Life Assessment System
- RTJ Flange Special Ultrasonic Testing
