Visual and optical Testing

A visual inspection is an essential and basic non-destructive inspection technique.
The external condition of a part can provide essential information on its condition:

• obvious flaws (such as folds, breaks, wear, corrosion, open cracks, etc.)
  
• underlying hidden defects presenting an external surface irregularity can indicate a more serious fault within
  
• choice of the most appropriate NDT technique for more detailed examinations
  
• determination of the limitations of the other NDT techniques chosen (access, surface condition, etc.)

Seal integrity tests, pneumatic tests and hydraulic tests also comprise a visual examination to reveal any leaks.