APPENDIX

(Nonmandatory Information)

X1. Comparison of Selected NDE Methods

MethodProperties Sensed

or Measured

TypicalDiscontinuities

Detected

RepresentativeApplications

Selected ASTMStandards

Advantages Limitations

X and gammaradiography

Changes in densityfrom voids, inclusions,

material variations,placement of internal

parts.

Voids, porosity,inclusions, cracks,

corrosion.

Castings, weldments,assemblies, explosives,detection of corrosion/material loss, location/dimension of internal

structures.

E94 E431 E592E746 E747 E801

E999 E1030E1032 E1316

E1742

Detects internal discon-tinuities; useful on a

wide variety of materi-als; portable; perma-

nent record.

Relative insensitivity tothin or laminar flaws

such as fatigue cracks ordelaminations which areperpendicular to the ra-

diation beam.

Neutronradiography

Compositional inhomo-geneities

Presence, absence,or mislocation of com-ponents or variationsof suitable composi-

tion

Ordnance, Castings,O-Rings

E545 E748 E803E1496

Good penetration ofmost structural metals;high sensitivity to favor-able materials; perma-nent record. High spa-

tial resolution

Relatively unportable.Thick sections of

hydrogen-containing ma-terials; limited facilities

Liquid penetrantexamination

Surface openings. Cracks, porosity, laps,and seams.

Castings, forgings,weldments, metallic andnonmetallic components.

E165 E433E1316 E1417

Inexpensive; easy toapply; portable.

Discontinuity must beopen to an accessible

surface; false indicationsoften occur.

Eddy currentexamination

Changes in electricaland magnetic proper-ties caused by surfaceand near-surface dis-

continuities.

Cracks, seams, laps,voids, and variationsin alloy compositionand heat treatment.

Bars, rods, wire, tubing,local regions of sheet

metal, alloy sorting, andthickness gaging.

E215 E243 E309E376 E426 E566E571 E690 E703

E1004 E1316E1606 E1629E2261 E2338

Moderate cost; readilyautomated; portable;permanent record if

needed.

Conductive materialsonly; shallow penetration;geometry sensitive; refer-

ence standards oftennecessary.

Microwaveexamination

Anomalies in complexdielectric coefficientsurface anomalies inconductive materials.

In dielectrics: dis-bonds voids, and

cracks; in metal sur-faces: surface cracks.

Glass-fiber-resin struc-tures; plastics; ceramics;moisture content; thick-

ness measurement.

Non contacting; readilyautomated; rapid ex-

amination.

No penetration of metals;comparatively poordefinition of flaws.

Magnetic particleexamination

Leakage in magneticfield flux caused by

surface or near-surfacediscontinuities.

Surface or near-surface cracks, laps,

voids, and nonmetallicinclusions.

Ferromagnetic productssuch as weldments,

castings, forgings, andextrusions, and other ba-

sic steel products.

E125 E709E1316 E1444

Stable; inexpensive Ferromagnetic materialsonly; surface preparationmay be required; falseindications often occur.

Magnetic fluxleakage examina-

tion

Leakage in magneticfield flux caused by

surface or near-surfacediscontinuities.

Surface or near-surface cracks, laps,

voids, and nonmetallicinclusions.

Ferromagnetic productssuch as weldments,

castings, forgings, andextrusions, and other ba-

sic steel products.

E570 E1571 Sensitivity to typicaldiscontinuities; readilyautomated; moderate

depth penetration; per-manent record, if

needed.

Ferromagnetic materialsonly; proper magnetiza-tion of part sometimesdifficult when parts donot have uniform cross

section.

Ultrasonicexamination

Changes in acousticimpedance.

Cracks, voids,porosity, lamination,delaminations, and

inclusions.

Weldments, plates, tubes,castings, forgings, extru-sions; thickness gaging.

E114 E127 E164E213 E273 E317

E428 E494E587 E797

E1001 E1315E1316 E1774E1816 E1901E1961 E1962E2001 E2192E2223 E2373E2375 E2479E2491 E2534E2580 E2700

Excellent penetration;readily automated;

good sensitivity andresolution; requires ac-cess to only one side;permanent record, if

needed.

Requires acoustic cou-pling to surface; refer-ence standard usuallyrequired; highly depen-dent upon operator skill;relative insensitivity to

laminar flaws which areparallel to the sound

beam.

Sonic examination Changes in acousticimpedance.

Disbonds,delaminations, cracks,

or voids.

Laminated structures;honeycomb; small parts.

Simple to implement;readily automated; por-

table.

Geometry sensitive; poordefinition.

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TABLE X1 Continued

MethodProperties Sensed

or Measured

TypicalDiscontinuities

Detected

RepresentativeApplications

Selected ASTMStandards

Advantages Limitations

Ultrasonicholography

Same as ultrasonicexamination.

Used primarily forevaluation ofdiscontinuities

detected by othermethods.

Examination of a limitedregion of the structure in

each image.

Produces a viewableimage of discontinuities.

Cost; limited to smallregions of the structure;poor definition compared

to radiography.

Infrared testing Surface temperature;anomalies in thermal

conductivity or surfaceemissivity, or both.

Voids or disbonds innonmetallics; locationof hot or cold spots in

thermally activeassemblies.

Laminated structures;honeycomb; electric and

electronic circuits;insulated structures;

refractory linedstructures and machinery.

Produces a viewablethermal map.

Cost; difficult to controlsurface emissivity; poor

definition.

Strain gauges Mechanical strains. Not used for detectionof discontinuities.

Stress-strain analysis ofmost materials.

Low cost; reliable. Insensitive to preexistingstrains; small areacoverage; requiresbonding to surface.

Brittle coatings Mechanical strains. Not commonly usedfor detection ofdiscontinuities.

Stress-strain analysis ofmost materials.

Low cost; produceslarge area map of strain

field.

Insensitive to preexistingstrains.

Optical holography Mechanical strains. Disbonds;delaminations;

plastic deformation.

Honeycomb; compositestructures; tires; precision

parts such as bearingelements.

Extremely sensitive,produces map of strainfield; permanent record

if needed.

Cost; complexity;requires considerable

skill.

Leak detection Pressure changes,bubbles, acoustic hiss,

or the passage of atracer fluid through apressure boundary.

Leaks in closedsystems.

Vacuum systems; gasand liquid storagevessels; piping.

E427 E432 E479E493 E498 E499

E515 E908E1316

Good sensitivity; widerange of instrumenta-

tion available.

Requires internal andexternal access to sys-tem; contaminants mayinterfere; can be costly.

Acoustic emission Stress wave energygenerated by growingflaws, areas of high

stress, leaks.

Cracks, structuralanomalies, leaks, also

delamination, fiberfracture and matrixfailure in composite

materials.

Crack detection and loca-tion during proof testing,

crack propagation,composite, structures,

metal structures, rotatingequipment.

E569 E650 E749E750 E751

100% volumetric exami-nation in real time,

complicatedgeometries, very highsensitivity, permanentrecord, accurate flaw

location.

Structure must beloaded, sensors must bein contact with structure.

SUMMARY OF CHANGES

Committee E07 has identified the location of selected changes to this standard since the last issue (E543 – 09)that may impact the use of this standard. (March 1, 2013)

(1) Corrected title of SNT-TC-1A, CP-189 and NAS-410 insubsection 2.2.(2) Added new ultrasonic standards to subsection 2.1, NoteA1.5, Appendix X1, and revised A1.6.1.1.

(3) Deleted references to E214 (withdrawn).

E543 − 13

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