ndt adv

METHOD ADVANTAGES DISADVANTAGES VISUAL Inexpensive Highly portable Immediate results Minimum training Minimum part preparation Surface discontinuities only Generally only large discontinuities Misinterpretation of scratches DYE PENETRANT Portable Inexpensive Sensitive to very small discontinuities 30 min. or less to accomplish Minimum skill required Locate surface defects only Rough or porous surfaces interfere with test Part preparation required (removal of finishes and sealant, etc.) High degree of cleanliness required Direct visual detection of results required MAGNETIC PARTICLE Can be portable Inexpensive Sensitive to small discontinuities Immediate results Moderate skill required Detects surface and subsurface discontinuities Relatively fast Surface must be accessible Rough surfaces interfere with test Part preparation required (removal of finishes and sealant, etc.) Semi- directional requiring general orientation of field to discontinuity Ferro-magnetic materials only Part must be demagnetized after test. EDDY CURRENT Portable Detects surface and subsurface discontinuities Moderate speed Immediate results Sensitive to small discontinuities Thickness sensitive Surface must be accessible to probe Rough surfaces interfere with test Electrically conductive materials Skill and training required Time consuming for large areas Can detect many variables ULTRASONIC Portable Inexpensive Sensitive to very small discontinuities Immediate results Little part preparation Wide range of materials and thickness can be inspected Surface must be accessible to probe Rough surfaces interfere with test Highly sensitive to sound beam discontinuity orientation High degree of skill required to set up and interpret Couplant usually required X-RAY RADIOGRAPHY Detects surface and internal flaws Can inspect hidden areas Permanent test record obtained Minimum part preparation Safety hazard Very expensive (slow process) Highly directional, sensitive to flaw orientation High degree of skill and experience required for exposure and interpretation Depth of discontinuity not indicated ISOTOPE RADIOGRAPHY Portable Less expensive than X-ray Detects surface and internal flaws Can inspect hidden areas Permanent test record obtained Minimum part preparation Safety hazard Must conform to Federal and State regulations for handling and use Highly directional, sensitive to flaw orientation High degree of skill and experience required for exposure and interpretation Depth of discontinuity not indicated

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METHOD ADVANTAGES DISADVANTAGES

VISUALInexpensive Highly portableImmediate results Minimumtraining Minimum part preparation

Surface discontinuities only Generally only largediscontinuities Misinterpretation of scratches

DYEPENETRANT Portable Inexpensive Sensitive tovery small discontinuities 30 min.

or less to accomplish Minimumskill required

Locate surface defects only Rough or poroussurfaces interfere with test Part preparationrequired (removal of finishes and sealant, etc.)High degree of cleanliness required Direct visualdetection of results required

MAGNETICPARTICLE

Can be portable InexpensiveSensitive to small discontinuitiesImmediate results Moderate skillrequired Detects surface andsubsurface discontinuitiesRelatively fast

Surface must be accessible Rough surfacesinterfere with test Part preparation required(removal of finishes and sealant, etc.) Semi-directional requiring general orientation of field todiscontinuity Ferro-magnetic materials only Partmust be demagnetized after test.

EDDY CURRENT Portable Detects surface andsubsurface discontinuitiesModerate speed Immediate resultsSensitive to small discontinuitiesThickness sensitive

Surface must be accessible to probe Roughsurfaces interfere with test Electrically conductivematerials Skill and training required Timeconsuming for large areas

Can detect many variablesULTRASONIC Portable Inexpensive Sensitive to

very small discontinuitiesImmediate results Little partpreparation Wide range ofmaterials and thickness can beinspected

Surface must be accessible to probe Roughsurfaces interfere with test Highly sensitive tosound beam discontinuity orientation High degreeof skill required to set up and interpret Couplantusually required

X-RAYRADIOGRAPHY

Detects surface and internal flawsCan inspect hidden areasPermanent test record obtainedMinimum part preparation

Safety hazard Very expensive (slow process)Highly directional, sensitive to flaw orientationHigh degree of skill and experience required forexposure and interpretation Depth of discontinuitynot indicated

ISOTOPERADIOGRAPHY

Portable Less expensive than X-rayDetects surface and internal flawsCan inspect hidden areasPermanent test record obtainedMinimum part preparation

Safety hazard Must conform to Federal and Stateregulations for handling and use Highlydirectional, sensitive to flaw orientation Highdegree of skill and experience required forexposure and interpretation Depth of discontinuitynot indicated