BasicknowledgeofNonDestructiveTesting(NDT)andDestructiveTesting(DT)

1.WhatisNonDestructiveTesting(NDT)?

NDTisthetestingofmaterialstodetectinternalandsurfacedefectsordiscontinuitiesusingmethodswhichdonotdamageordestroythematerialundertest

2.WhatisthedifferentbetweenDefectsordiscontinuities?

Discontinuities:Anyimperfectionorinterruptioninthenormalphysicalstructureorconfigurationofaproduct(cracks,laps,inclusion,etc).Discontinuitymayormaynotaffecttheusefulnessoftheproduct

Defect:Adiscontinuitywhosesize,shape,orientation,locationorpropertiesmakesitdetrimentaltotheusefulserviceoftheproductinwhichitoccursorexceedstheaccept/rejectcriteriaforthegivendesign.Defectisatypeofdiscontinuity.

3.Whatarethemajor5NDTmethods?

Themajor5NDTMethodsare:

a.UltrasonicTesting

b.RadiographyTesting

c.MagneticParticleTesting

d.DyePenetrantTesting

e.EddyCurrentTesting

4.FordetectionofsurfacewelddefectsordiscontinuitieswhataretheNDTmethodscommonlyused?

TheNDTmethodsarecommonlyusedtodetectthedefect/discontinuitiesonsurfaceweld:

a.VisualTesting(VT)

b.PenetrantTesting(PT)

c.MagneticParticleTesting(MT)

d.EddyCurrentTesting(ET)

5.Fordetectionofinternalwelddefectsordiscontinuities,materialwhataretheNDTmethodscommonlyused?

TheNDTmethodstodetectinternalwelddefect/discontinuities:

a.RadiographicTesting(RT)

b.UltrasonicTesting(UT)

6.WhatarethefactorsaffectingthechoiceofNDTmethod

Dependsonmanyfactorsandconditions

a.Cost

b.Typeofdefectsought

c.Typeofmaterialtobetested

d.Positionandlocationofdefect

e.Availabilityofequipment

f.Availabilityofqualifiedoperators

g.Workingconditionsandlocation

h.Sensitivityrequired

i.others

7.WhatisDestructiveTesting(DT)?

DestructiveTestingisthetestingofmaterialstodetectinternalandsurfacedefectsordiscontinuitiesbymethodswhichdamagingordestroyingthematerialundertest

8.WhataretheDT(DestructiveTesting)methodswidelyapplied?

TheDTmethodswidelyusedareasfollows:

a.TensileTest

b.BendTest

c.CharpyTest

d.VickerTest

e.FractureTest

f.FatigueTest

g.CreepTest

h.Replica

EddyCurrentTestingLevelI(20Questions)

Q.1Generationofeddycurrentsdependsontheprincipleof:

A.waveguidetheory.

B.electromagneticinduction.

C.magnetorestrictiveforces.

D.alloftheabove.

Q.2Asecondaryfieldisgeneratedbythetestobjectandis:

A.equalandoppositetotheprimaryfield.

B.oppositetotheprimaryfield,butmuchsmaller.

C.inthesameplaneasthecoiliswound.

D.inphasewiththeprimaryfield.

Q.3Whenanonferromagneticpartisplacedinthetestcoil,thecoil'svoltage:

A.increases.

B.remainsconstantbecausethisisessential.

C.decreases.

D.shifts90degreesinphase.

Q.4Eddycurrentsgeneratedinatestobjectflow:

A.inthesameplaneasmagneticflux.

B.inthesameplaneasthecoiliswound.

C.90degreestothecoilwindingplane.

D.Eddycurrentshavenopredictabledirection.

Q.5Thediscoveryofelectromagneticinductioniscreditedto:

A.Arago.

B.Oersted.

C.Maxwell.

D.Faraday.

Q.6Astandarddepthofpenetrationisdefinedasthepointinatestobjectwheretherelativeeddycurrentdensityisreducedto:

A.25percent.

B.37percent.

C.50percent.

D.100percent.

Q.7Calculatethestandarddepthofpenetrationat10kHzincopper=5.7107mhospermeter.

A.0.1mm

B.0.02mm

C.0.66mm

D.66mm

Q.8Differentialcoilsareusuallyusedin:

A.bobbincoils.

B.probecoils.

C.ODcoils.

D.anyoftheabove.

Q.9Whenusingaprobecoiltoscanatestobject,______

A.theobjectmustbedryandpolished.

B.theobjectmustbescannedcarefullytoinsureinspectioncoverage.

C.theobjectmustbescannedincircularmotionsatconstantspeeds.

D.theprobemustbemovingatalltimestogetareading.

Q.10A"spinningprobe"wouldmostlikelybea(an):

A.bobbincoil.

B.IDcoil.

C.ODcoil.

D.probecoil.

Q.11A"feedthrough"coilis:

A.acoilwithprimary/secondarywindingsconnectedsothatthesignalisfedthroughtheprimarytothesecondary.

B.anencirclingcoil.

C.anODcoil.

D.bothBandC.

Q.12Wheninspectingatubularproductwithanencirclingcoil,whichstatementisnottrue?

A.ODdiscontinuitiescanbefound.

B.Axialdiscontinuitylocationscanbenoted.

C.Circumferentialdiscontinuitylocationscanbenoted.

D.IDdiscontinuitiescanbefound.

Q.13Anabsolutecoilmeasurementismade

A.bycomparingonespotonthetestobjecttoanother.

B.withoutreferencetoordirectcomparisonwithastandard.

C.onlywithprobecoils.

D.bycomparativemeasurementtoaknownstandard.

Q.14Whencoilsinadifferentialarrangementareaffectedsimultaneouslywiththesametestobjectvariables,theoutputsignal

A.isdirectlyproportionaltothenumberofvariables.

B.is"0"ornear"0."

C.isindirectlyproportionaltothenumberofvariables.

D.isprimarilyafunctionoftheexcitingcurrent.

Q.15Whichcoiltypeinherentlyhasbetterthermalstability?

A.Bobbin

B.Absolute

C.OD

D.Differential

Q.16Ahybridcoiliscomposedoftwoormorecoils.Thecoils

A.mustbealignedcoplanartothedriveraxis.

B.maybeofwidelydifferentdimensions.

C.mustbeimpedancematchedascloselyaspossible.

D.areverytemperaturesensitive.

Q.17Properselectionoftestcoilarrangementisdeterminedby:

A.shapeoftestobject.

B.resolutionrequired.

C.sensitivityrequired.

D.alloftheabove.

Q.18Acoil'sresistanceisdeterminedby:

A.wirematerial.

B.wirelength.

C.wirecrosssectionalarea.

D.alloftheabove.

Q.19Inductanceisanalogousto:

A.force.

B.volume.

C.inertia.

D.velocity.

Q.20Theunitofinductanceisthe:

A.henry.

B.maxwell.

C.ohm.

D.farad.

ANSWER

1.B 2.B 3.C 4.B 5.D 6.B 7.C 8.D 9.B 10.D

11.D 12.C 13.B 14.B 15.D 16.B 17.D 18.D 19.C 20.A

LiquidPenetrantTestingMethod(40Questions)

1.Whichoneofthefollowingconditionswillaffecttherateandtheextentaliquidpenetrantwillentercracks,fissures,andothersmallopenings?

a.thehardnessofthespecimenbeingtested

b.thesurfaceconditionofthespecimenbeingtested

c.thecolorofthepenetrant

d.theconductivityofthespecimenbeingtested

2.Whichofthefollowingisacommonlyusedclassificationforpenetrant?

a.postemulsifiablepenetrant

b.nonferrouspenetrant

c.chemicaletchpenetrant

d.nonaqueouspenetrant

3.Agenerallyacceptedmethodforremovingexcessnonwaterwashablepenetrantis:

a.repeatedlydippingthetestspecimeninacleaner

b.soakingthetestspecimeninhotdetergentwater

c.blowingtheexcesspenetrantoffthesurfaceofthepartwithcompressedair

d.wipingandcautiouslycleaningthetestspecimenwithacleanerdampenedcloth

4.Allofthefollowingpartscanbetestedbytheliquidpenetrantmethodexcept:

a.anironcasting

b.analuminumforging

c.apartmadefromaporousplasticmaterial

d.apartmadefromanonporousmaterial

5.Whichofthefollowingdiscontinuitiescanbefoundbythepenetranttestmethod?

a.asurfacecrack

b.asubsurfacecrack

c.aninternalinclusion

d.noneoftheabove

6. Which of the following is generally the more acceptable method for cleaning parts prior to penetrant testing?

a.sandblasting

b.wirebrushing

c.grinding

d.vapordegreasing

7.Allofthefollowingmethodsarecommonlyusedtocleanpartspriortopenetranttestingexcept:

a.vapordegreasing

b.liquidsolvent

c.powerwirebrushing

d.alkalinecleaner

8.Cuttingoilsmaybeeffectivelyremovedfrompartsbeforepenetranttestingby:

a.preheating

b.vapordegreasing

c.washingwithwater

d.alloftheabove

9.Themostcommontypeofcontaminantinfluorescentpenetrantfluidis:

a.metalfilings

b.oil

c.detergents(fromcleaning)

d.water

10. Black light, with a proper functioning filter in place, used for fluorescent penetrant inspection can causepermanentdamageto:

a.humantissues

b.humaneyes

c.humanbloodcells

d.noneoftheabove

11.Allofthefollowingbasicinspectionprinciplesapplytothepenetrantmethodsexcept

a.thepenetrantmustenterthediscontinuityinordertoformanindication

b.indicationsglowwhenilluminatedwithablacklight

c.alongerpenetrationtimeisrequiredforsmallerdiscontinuities

d.ifthepenetrantiswashedoutofthediscontinuity,anindicationwillnotbeformedbythatdiscontinuity

12.Subsurfacediscontinuitiescanbebestdetectedby:

a.thepostemulsificationpenetrantmethod

b.thevisibledyepenetrantmethod

c.thefluorescent,waterwashablepenetrantmethod

d.noneoftheabove

13.Visiblepenetrantmaybeappliedby:

a.brushing

b.spraying

c.dipping

d.noneoftheabove

14.Thefirststepinconductingaliquidpenetranttestonasurfacethathasbeenpaintedisto:

a.carefullyapplythepenetrantoverthesurface

b.completelyremovethepaint

c.thoroughlywashthesurfacewithadetergent

d.wirebrushthesurfacetoroughenthesmoothsurfacecoatingofpaint

15.Whenusingapostemulsificationpenetrant,itisnecessarytoapplytheemulsifier:

a.beforeapplyingthepenetrant

b.afterthewaterwashoperation

c.afterthedwelltimehaselapsed

d.afterthedevelonmenttimehaselapsed

16.Whenconductingawaterwashableliquidpenetranttest,thewetdeveloperisapplied:

a.immediatelyafterthepenetranthasbeenapplied

b.immediatelybeforethepenetrantisapplied

c.afterremovalofthepenetrant

d.afterremovaloftheemulsifier

17. The term used to describe the action of a particular developer in soaking up the penetrant in a discontinuity, so as to cause the maximum bleedout of the liquid penetrant for increased contrast and sensitivity,isknownas:

a.blotting

b.capillaryaction

c.concentration

d.attraction

18. Using a black light lamp with a cracked filter or without the filter in place can cause damage to humaneyesbecausethelampemits:

a.blacklight

b.ultravioletlight

c.infraredlight

d.noneoftheabove

19.Thetermusedtodefinetheperiodoftimeinwhichthetestpartiscoveredwithpenetrantis:

a.waitingtime

b.soaktime(draintime)

c.penetrationtime(dwelltime)

d.bleedintime

20. Usually, the most desirable method of removing excess waterwashable penetrant after the dwell timeisbyusing:

a.alowpressurecoarsewaterspray

b.waterandbrush

c.asolidstreamofwater

d.waterandcleanrags

21. When conducting a liquid penetrant test using a post emulsifiable visible dye penetrant, the generally acceptedmethodforapplyingthewetdeveloperisby:

a.brushing

b.swabbing

c.dipping

d.spraying

22.Whichofthefollowingcharacteristicsdoesnotapplytoliquidpenetranttesting?

a.thismethodcanaccuratelymeasurethedepthofacrackordiscontinuity

b.thismethodcanbeusedforonsitetestingoflargeparts

c.thismethodcanbeusedtofindshallowsurfacediscontinuities

d.thismethodcanbemademoreorlesssensitivebyusingdifferentpenetrantmaterials

23.Whichofthefollowingdiscontinuitiesismostlikelytobemissedduetoimproperrinsetechniques?

a.aforginglap

b.deeppitting

c.shallowandbroaddiscontinuities

d.therinsetechniquewillnotaffectthedetectionofdiscontinuities

24. When conducting a fluorescent penetrant test, a commonly used technique for assuring that the excesspenetranthasbeenremovedpriortotheapplicationofadeveloperisto:

a.blowcompressedairoverthesurface

b.chemicallyetchthesurface

c.blotthesurfacewithabsorbentpaper

d.scanthesurfacewithablacklight

25.Whichofthefollowingsurfaceconditionscouldhaveadetrimentaleffectonaliquidpenetranttest?

a.awetsurface

b.aroughweld

c.anoilysurface

d.alloftheabove

26.Liquidpenetranttestingiscapableofdetecting:

a.intergranularstresscorrosioncrackingdiscontinuities

b.discontinuitiesopentothesurface

c.subsurfacediscontinuities

d.alloftheabove

27.Blacklightequipmentisrequiredwhenpenetranttestingby:

a.the.fluorescentpenetrantmethod

b.thevisibledyepenetrantmethod

c.thenonfluorescentpenetrantmethod

d.alloftheabove

28. The term used to define the tendency of certain liquids to penetrate into small openings such as cracksorfissuresis:

a.saturation

b.capillaryaction

c.blotting

d.wettingagent

29. Excess penetrant (all penetrant except that which is in discontinuities) is removed from the specimen:

a.aftertherequiredpenetrantdwelltimehaselapsed

b.beforetheapplicationofanemulsifierifapostemulsifierpenetrantisused

c.bymeansofasteamcleaner

d.onlywhenwaterwashablepenetrantsareused

30.Whenusingapostemulsifiablepenetrant,theemulsifiertimeshouldbe:

a.aslongasthepenetrantdwelltime

b.halfthepenetrantdwelltime

c.thesameasthedevelopertime

d.onlyaslongasnecessarytoremovetheinterferingbackground

31. When an inspector is working in a darkened area, he/she should become adjusted to the dark before inspectingparts.Thegenerallyacceptedtimeperiodforbecomingaccustomedtothedarkis:

a.1minute

b.5to0minutes

c.10to15minutes

d.nowaitingperiodisnecessary

32.Whenapplyingpenetrantbydipping,heatingthepenetrantpriortodipping:

a.willincreasethesensitivityofthetest

b.willincreasethecapillaryactionofthepenetrant

c.willincreasethestabilityofthepenetrant

d.isnotgenerallyrecommended

33.Apenetrantinspectioncannotfind:

a.surfaceporosity

b.surfacecracks

c.aninternalcavity

d.asurfaceforginglap

34.Allofthefollowingmaterialscanbetestedbytheusualliquidpenetranttestsexcept:

a.unglazedporouscerai

b.titanium

c.highalloysteel

d.castiron

35.Liquidpenetranttestingcanbeusedtodetect:

a.discontinuities1.6mm(0.06in.)belowthesurface

b.internaldiscontinuities

c.discontinuitiesopentothesurface

d.alldiscontinuities

36.Whichofthefollowingarecommonlyacceptedmethodsforapplyingpenetrant?

a.dippingthepartinpenetrant(dipping)

b.pouringthepenetrantoverthetestspecimen(flowing)

c.sprayingthepenetrantonthetestspecimen(spraying)

d.alloftheabove

37. A solvent used to clean the surface of a test specimen must possess all of the following characteristicsexceptthatthe:

a.cleanermustbecapableofdissolvingoilsandgreasescommonlyfoundonthesurface

b.cleanermustnotbeflammable

c.cleanermustbefreeofcontaminants

d.cleanermustleaveaminimalresidueonthesurface

38. Which of the statements below best states the danger of sandblasting (without subsequent chemical etching)forcleaningsurfacestobepenetranttested?

a.thediscontinuitiesmaybepeenedoverandclosed

b.oilcontaminantsmightbesealedinthediscontinuities

c.thesandusedinthesandblastingoperationmaybeforcedintothediscontinuity

d.thesandblastingoperationmayintroducediscontinuities

39.Thepenetrantappliedtothesurfaceofatestspecimen:

a.seepsintodiscontinuities

b.isabsorbedbydiscontinuities

c.isdrawnintodiscontinuitiesbycapillaryaction

d.isdrawnintodiscontinuitiesbygravity

40.Whichofthefollowingstatementsconcerningliquidpenetranttestingiscorrect?

a.fluorescentpenetrantswillproduceredagainstwhitediscontinuityindications

b.nonfluorescentpenetrantsrequiretheuseofblacklights

c.fluorescentindicationswillbeseenwhenexposedtoblacklight

d.nonfluorescentdiscontinuitiesglowinthedarkforeasyviewingandinterpretation

ANSWER

1.B 2.A 3.D 4.C 5.A 6.D 7.C 8.B 9.D 10.D

11.B 12.D 13.D 14.B 15.C 16.C 17.A 18.B 19.C 20.A

21.D 22.A 23.C 24.D 25.D 26.B 27.A 28.B 29.A 30.D

31.B 32.D 33.C 34.A 35.C 36.D 37.B 38.A 39.C 40.C