INTRODUCTION TO NDT
Non-Destructive Testing (NDT) is a group of testing techniques used to evaluate the properties of a material, component, or assembly without causing damage to it. NDT plays a crucial role in ensuring the safety, reliability, and performance of materials and structures in various industries, including aerospace, construction, automotive, and manufacturing.
NDT methods help detect internal and external flaws or defects in materials such as cracks, lack of fusion, lack of penetration, porosity, slag, corrosion, voids, and weld inconsistencies. These methods include visual inspection, ultrasonic testing, radiographic testing, magnetic particle testing, eddy current testing, and liquid penetrant testing, etc.
The main advantage of NDT is that it allows for inspection and evaluation without damaging the object being tested, meaning the object remains usable after the inspection. This makes it an essential tool in ensuring the quality and safety of critical structures and systems.
In short NDT helps us to examine the material/object without harming the material and same material can be use in future without any discripencies.
NDT TECHNIQUES
Common techniques include:
- Liquid Penetrant Testing (LPT)
- Visual Inspection
- Ultrasonic Testing (UT)
- Radiographic Testing (RT)
- Magnetic Particle Testing (MPT)
- Positive Material Identification (PMI)
NDT TYPES
NDT LEVELS
Levels of qualification include:
- Level I: Can perform specific calibrations and evaluations.
- Level II: Can set up and calibrate equipment, interpret results, and supervise Level I personnel.
- Level III: Can establish techniques and procedures, and have administrative responsibility.
NDT QUALIFICATIONS
NDT technicians typically require formal training and certification such as ASNT, ISO 9712, or equivalent. Certifications ensure standardized skills and practices across industries.
NDT REFERENCE STANDARDS
Some important standards include:
- ASTM E1444 for MPT
- ASTM E165 for LPT
- ASTM E1030 for UT
- ISO 9712 for Personnel Qualification
- ASME Section V for NDT techniques