Technical Notes
Technical Notes
FAQ - Non-Destructive Testing (NDT)
Q01) What is NDT?
Q02) What are the most common NDT testing methods?
Q03) What's the difference between NDT and Visual Inspection?
Q04) Why would I need NDT?
Q05) Why would I need Visual Inspections?
Q06) What inspection services does Domson offer?
NDT is an acronym for Non Destructive Testing. It is also refered to as Non Destructive Inspection, or Non Destructive Evaluation. NDT is exactly what its name implies, testing in which the part or material being evaluated is neither damaged nor destroyed. NDT covers a broad range of testing methods, including magnetic particle, liquid penetrant, ultrasonics, visual inspection and vibration analysis to name a few.
Q02) What are the most common NDT testing methods?
The ten most common NDT methods are:
- Magnetic Particle
- Ultrasonics
- Liquid Penetrant
- Visual Inspection
- Vibration Analysis
- Radiography
- Eddy Current
- Infrared Thermography
- Leak Testing
- Acoustic Emmission
Q03) What's the difference between NDT and Visual Inspection?
In Canada, NDT is regulated by the Canadian General Standards Board (CGSB). The CGSB handles all training and certification of personnel in the various NDT fields, including magnetic particle, ultrasonics, etc. Although visual inspection is classed as a subset of NDT, it is different from the rest in that it is seperately regulated by the Canadian Welding Bureau (CWB).
NDT methods are often employed as a means of quality control, or as a maintenance requirement.
An example of the former would be the inspection of a weld on a manbasket during manufacture. Here magnetic particle would be employed to check for hydrogen cracking in the weld. An example of the latter would be the inspection of that same weld after the basket has been in service for 12 months. In this case, magnetic particle would again be used to check the weld, however, this time, the inspector would be looking for fatigue cracks.
Q05) Why would I need Visual Inspections?
Visual inspections play a key role in areas where welding is involved. Visual inspectors ensure that weldments are made to specifications and that they pass all rejection criteria. Although this NDT method may seem trivial when compared to the other methods that employ sophisticated equipment, it is one of the most difficult in which to obtain a certification.
Q06) What inspection services does Domson offer?
Domson offers the following inspection methods:
- Magnetic Particle
- Ultrasonics
- Liquid Penetrant
- Eddy Current & Remote Field
- Visual Inspection
- Vibration Analysis
All our personnel are appropriately trained and certified (under CGSB or CWB) in their respective inspection methods.