Advantages:

• It shows surface and near surface defects, and these are the most serious ones as they concentrate stresses
• Sensitive to small indications
• Semi-portable
• Sensitive to inclusions as well as cracks
• The method can be adapted for site or workshop use
• Large or small objects can be examined

Advantages:

• High sensitivity to small surface discontinuities
• Easy inspection of parts with complex shapes
• Few material limitations( magnetic & nonmagnetic, metallic & non-metallic, stainless steel, aluminium can all be tested)
• A visual representation of the flaw are indicated directly on the part surface
• Aerosol spray cans make the process portable
• Indications can relative size, shape and depth of the flaw

Advantages:

• It is sensitive to both surface and subsurface discontinuities.
• The depth of penetration for flaw detection or measurement is superior to other NDT methods.
• Only single-sided access is needed when the pulse-echo technique is used.
• It is highly accurate in determining reflector position and estimating size and shape.
• Electronic equipment provides instantaneous results.
• It has other uses, such as thickness measurement, in addition to flaw detection.

Wall Thickness

• Does not require access to both sides of the sample
• Can be engineered to cope with coatings, linings, etc
• Good accuracy (0.1 mm and less) can be achieved using standard timing techniques
• Can be easily deployed, does not require laboratory conditions
• Digital UTM gives directly Thickness on display.
• Detection on erosion and corrosion damages occurred in service