无损检测论文无损检测技术论文检测论文（nondestructive testing papers, nondestructive testing techniques, papers, papers）

无损检测论文无损检测技术论文检测论文（NONDESTRUCTIVETESTINGPAPERS,NONDESTRUCTIVETESTINGTECHNIQUES,PAPERS,PAPERS）THISARTICLEISCONTRIBUTEDBYWORKLVPDFDOCUMENTSMAYEXPERIENCEPOORBROWSINGONTHEWAPSIDEITISRECOMMENDEDTHATYOUFIRSTSELECTTXT,ORDOWNLOADTHESOURCEFILETOTHELOCALVIEWINNERMONGOLIAELECTRICPOWERTECHNOLOGY2010VOLSIXTH,PHASEINNERMONGOLIAELECTRICPOWERTHIRTYTHREEAPPLICATIONOFULTRASONICTIMEDIFFERENCEMETHODINNONDESTRUCTIVETESTINGOFPOWERPLANTEQUIPMENTAPPLICATION,RESEARCH,OF,ULTRASONIC,TOFD,TESTING,IN,POWER,STATION,NONDESTRUCTIVE,TESTINGTIANLI,MALE,WEIZHIGANG,ZHANGINNERMONGOLIAELECTRICPOWERRESEARCHINSTITUTE,INNERMONGOLIATAO,ZHANGYANFEIHOHHOT010020ABSTRACTDIFFRACTIONTIMEDIFFERENCEULTRASONICTESTINGTOFDTECHNOLOGYISANEWTYPEOFDETECTIONTECHNOLOGY,COMPAREDWITHCONVENTIONALULTRASONICTESTING,ITHASGREATADVANTAGESTHEOMNISCANMXSCANNINGINSTRUMENTISUSEDTOREFITTHESCANNINGDEVICE,ANDASPECIALTESTBLOCKISDESIGNEDANDMANUFACTUREDDETECTIONPARAMETERS,ANDMAKEASPECIFICTOFDDETECTIONPROCEDURES,THEBLOCKSARENONPARALLELSCANNINGTODETECTTHESPECIALTESTBLOCKSOFDIFFERENTNATURE,DIFFERENTDIRECTIONSOFALLDEFECTS,ANDIMAGINGINTUITIVE,EASYTOIDENTIFYTHETOFDDETECTIONTECHNIQUEISAPPLIEDTONONDESTRUCTIVETESTOFPOWERPLANTEQUIPMENT,ANDBETTERRESULTSAREOBTAINEDRESEARCHSHOWSTHATTOFDDETECTIONTECHNOLOGYCANIMPROVETHEDETECTIONRATEOFDEFECTSANDREDUCETHERATEOFFALSEPOSITIVES,BUTTHEREARESOMELIMITATIONSKEYWORDSDIFFRACTIONTIMEDIFFERENCEMETHODULTRASONICTESTINGNONDESTRUCTIVETESTINGWELDDEFECTSPOWERPLANTEQUIPMENTTHEOMNISCANMXTESTERDOCUMENTCODEB10086218ARTICLENUMBER2010060033051OVERVIEWOFTOFDTECHNOLOGYONEPOINTONEDEVELOPMENTSTATUSINTHISCASE,THERECEIVINGPROBERECEIVESTHETHROUGHWAVEFIRSTANDFINALLYRECEIVESTHEREFLECTEDWAVEATTHEBOTTOMIFTHEREISADEFECT,THEDIFFRACTIONWAVEOFTHEDEFECTENDPOINTORBOUNDARYWILLALSOBERECEIVEDBETWEENTHEDIRECTWAVEANDTHEBOTTOMREFLECTEDWAVE,ASSHOWNINFIGURE1THEWAVESIGNALSAREINITIALLYREPRESENTEDASASCANNINGSIGNALS,ANDTHECOORDINATEVALUESRECEIVEDBYTHEPOSITIONENCODERARERECEIVEDBYTHEHOSTCOMPUTERANDPROCESSEDBYDIGITALIMAGE,THUSFORMINGATWODIMENSIONALIMAGESCANNINGDISPLAYOFB,DANDTHELIKETHERESEARCHERSMAINLYCONDUCTEDQUALITATIVE,QUANTITATIVEANDQUANTITATIVEANALYSISOFTHEDEFECTSBASEDONTHESEDISPLAYS2WELDLINEIN1970S,TOFDOFFLIGHTTIMEDIFFRACTIONWASINTRODUCEDINTHEUNITEDKINGDOMITWASORIGINALLYAPPLIEDTOTHETHICKWALLPRESSUREVESSELOFNUCLEARREACTORTODETECT1ATTHEENDOFTHETWENTIETHCENTURY,WITHTHERAPIDDEVELOPMENTOFCOMPUTERTECHNOLOGY,THENUMBERANDNUMBEROFTOFDTECHNOLOGYCOMBINEDWITHULTRASONICEQUIPMENT,ITHASDEVELOPEDINTOAKINDOFULTRASONICIMAGINGTESTINGTECHNOLOGYATTHEBEGINNINGOFTWENTYFIRSTCENTURY,TOFDWASINTRODUCEDINTOOURCOUNTRYINTHEWESTEASTGASPIPELINEANDSHENHUACOALLIQUEFACTIONPROJECTAPPLICATION,THETOFDTECHNOLOGYHASBEENWIDELYUSEDINAEROSPACE,NUCLEARINDUSTRY,ELECTRICPOWER,MACHINERYMANUFACTURING,PETROLEUMANDCHEMICALINDUSTRYEMISSIONPROBESCANNINGDIRECTIONRECEIVINGPROBESOUNDBEAMINWELDONEPOINTTWODETECTIONPRINCIPLETOFDARE1NEWULTRASONICTESTINGTECHNIQUES,ITCANBEPASSEDOVERTHETIPOFTHEACOUSTICWAVEISUSEDTODETECTDEFECTS,ANDDEFECTSAREMEASUREDBYWAVEPROPAGATIONTIMEDIFFERENCE,ANDTHEDEFECTSAREDISPLAYEDBYTHEIMAGEPROCESSINGOFTHESIGNAL1WHENTOFDISDETECTED,THEPROBEISFIREDCOMMONLYEPUB20100610FIGURE1TOFDSCANNINGSKETCHMAPONEPOINTTHREECOMPAREDWITHTHECONVENTIONALULTRASONICTESTINGTECHNOLOGY,THETOFDTECHNOLOGYMAINLYHASADVANTAGESANDDISADVANTAGESAUTHORTIANLI,MALE1968,MALE,INNERMONGOLIA,MASTER,SENIORENGINEER,ENGAGEDINNONDESTRUCTIVETESTINGANDMETALTECHNOLOGYSUPERVISIONPROJECTINNERMONGOLIAELECTRICPOWERRESEARCHINSTITUTE,2008,SELFFINANCINGRESEARCHPROJECTTHIRTYFOUR3HASTHEFOLLOWINGADVANTAGESINNERMONGOLIAELECTRICPOWERTECHNOLOGY2010VOLUMESIXTH,ISSUETWENTYEIGHTHTHREEDESIGNANDPROCESSINGOFSPECIALTESTBLOCKAIMINGATTHESTRUCTUREOFWELDINGSEAMOFUTILITYBOILER,PRESSUREVESSELANDPRESSUREPIPE1THEMEASUREMENTACCURACYISHIGHUSUALLY1MM,ANDITCANMEASURETHEHEIGHTOFTHEDEFECT,BUTTHEREISACERTAINMEASUREMENTERRORCONVENTIONALULTRASONICTESTINGCANNOTMEASURETHEHEIGHTOFTHEDEFECTITSELF2THEDEFECTSINANYDIRECTIONOFTHEEFFECTIVEREGIONCANBEDETECTED3WITHTHEHELPOFBANDDSCANNING,THEDEFECTDETECTIONRATEANDTHEACCURACYOFDEFECTSAREEFFECTIVELYIMPROVED,ANDTHERATEOFFALSEPOSITIVESISREDUCED4THEINFORMATIONOFTHEWHOLEWELDSEAMCANBEOBTAINEDBYONESWEEP,ANDITCANBEANALYZEDOFFLINEHOWEVER,TOFDTECHNOLOGYISABRANCHOFULTRASONICTESTINGTECHNOLOGY,THEINHERENTLIMITATIONSOFULTRASONICTESTINGSTILLEXIST,FOREXAMPLE,ITISDIFFICULTTODETECTNEARSURFACEDEFECTSANDDIFFICULTTODETECTALLKINDSOFCOARSEGRAINMATERIALSTHECHARACTERISTICSANDTHETYPESANDDISTRIBUTIONOFWELDINGDEFECTS,DESIGNED10SPECIALTESTBLOCKTOFDD1TOFDD10,14OFTHEDEFECTPRODUCTIONINDIFFERENTPOSITIONOFSPECIMENS,INCLUDINGLACKOFFUSION,CRACKS,POROSITY,SLAGINCLUSION,INCOMPLETEPENETRATIONDEFECTS5THEWELDSTRUCTUREOFTHETESTBLOCKINCLUDESEQUALTHICKNESSBUTTJOINT,UNEQUALTHICKNESSBUTTJOINTANDTHEWRONGEDGEOFTHEROOTCOMMISSIONEDBYAWELDINGTRAININGCENTERINSHANDONG,ASPECIALMETHODWASUSEDTOPROCESSTHETESTBLOCKANDAPREPLANNEDARTIFICIALDEFECTWASFORMEDINTHEWELD,ASSHOWNINFIGURE4RADIOGRAPHICINSPECTIONOFTHEBLOCKAFTERPROCESSINGHASBEENDONESEEFIGURE52TOFDTESTINGEQUIPMENTANDCONFIGURATIONUSINGOMNISCANMXDETECTORMANUFACTUREDBYR/DTECHCANADANOWOLYMPUSCORPORATION,PROBES,WEDGESANDSIMPLESCANNINGRACKSSEEFIGURE2AREPROVIDEDTHESIMPLESCANNINGFRAMEISUSEDFORACTUALDETECTION,BUTTHELENGTHOFTHESTRAIGHTRODISONLY200MM,WHICHISDIFFICULTTOREALIZEUNDERDIFFERENTCIRCUMSTANCESFIG4PARTTOFDSPECIALTESTBLOCKTHESETTINGOFPCSTHEDISTANCEBETWEENTHEINCIDENTPOINTOFTHETRANSMITTINGPROBEANDTHERECEIVINGPROBE,THEREFORE,1ADDITIONALDIAMETERS,10MM,500MMLONGLONGSTRAIGHTRODFIGURE5,FIGURE2RADIOGRAPHICINSPECTIONRESULTSOFTESTBLOCKSOMNISCANMXDETECTOR,PROBE,WEDGEANDSIMPLESCANNINGRACKINADDITION,TOOLINGMODIFICATIONSWEREMADETO1SCANRACKSDEVELOPEDBYATESTEQUIPMENTCOMPANY,AWEDGEHOLDERANDANENCODERCLAMPINGDEVICEAREDESIGNEDANDFABRICATEDTOCONNECTWITHTHEWEDGEANDENCODERSETOFTHEOMNISCANMXTESTERTHESCANNINGRACKAFTERTOOLINGMODIFICATIONENABLESTHEPROBETOBECOUPLEDBETTERWITHTHEWORKPIECESEEFIGURE3FIELDTESTSSHOWTHATTHESTABILITYANDPRACTICABILITYOFTHESCANNINGAREBETTERTHANTHATOFTHEORIGINALSIMPLESCANNINGRACKFOURTOFDTESTPROGRAMANDPARAMETERSETTING4INDIFFERENTFIELDS,THEOBJECTSAREDETECTEDINMATERIAL,THICKNESSANDSTRUCTUREFORMS,DEFECTS,CHARACTERISTICS,ETCVARYFROMMANUFACTURERTOMANUFACTURERTOFDFLAWDETECTORALSOHASITSOWNCHARACTERISTICSANDOPERATIONMODETHEREFORE,ITISNECESSARYTOUSETOFDTECHNOLOGYTOCARRYOUTNONDESTRUCTIVETESTINGOFPOWERPLANTEQUIPMENTTHETESTPARAMETERSARESETUPACCORDINGTOTHETEST,ANDTHESPECIFICTESTPROCEDUREISWORKEDOUTPOSTCLAMPINGOFENCODERFOURPOINTONETOFDTESTPROGRAMAFTERREPEATEDTESTS,THEUTILITYMODELHASBEENCONFIRMEDTOBESUITABLEFORUTILITYBOILERSANDPRESSUREVESSELSENCODERFRONTCLAMPINGWEDGECLAMPTOFDTESTPROCEDUREFORBUTTJOINTOFPRESSUREPIPE411SCANNINGRACKAFTERMODIFICATIONOFTOOLINGTHEINSPECTIONAREASHALLBETHEWIDTHOFTHEWELDITSELFANDEACHSIDEOFTHEWELDFIGURE3WHENTHEBASEMETALTHICKNESSIS30,THEDETECTIONSURFACESHALLBESMOOTHANDROUGH2010VOLUMESIXTH,ISSUETWENTYEIGHTHINNERMONGOLIAELECTRICPOWERTECHNOLOGYTHIRTYFIVETHEROUGHNESSOFRAISLESSTHANOREQUALTO63M,GENERALLYNEEDTOBEPOLISHEDBECAUSETOFDUSES2KINDSINTHETOFDTESTOFPOWERPLANTEQUIPMENT,NONPARALLELSHOULDBEUSEDASFARASPOSSIBLESCANNING,DOESNOTRECOMMENDTHEUSEOFPARALLELSCAN,THISISBECAUSETHROUGHDETECTION,NONPARALLELSCANNINGCANCOMPLETEDEFECTQUANTITATIVEORQUALITATIVEDETECTIONOFALLCONTENT,BUTCANNOTJUDGETHEOTHERSIDEOFTHECENTERLINEOFTHEWELDDEFECTS,CANBECOMPLEMENTEDBYCONVENTIONALULTRASONICTESTINGPARALLELSCANOFDEFECTSONTHEOTHERSIDEMAYDETERMINETHEWELDTHECENTERLINE,BUTLOWDETECTIONEFFICIENCYANDDETECTION,BEFORETHENEEDTOSTRENGTHENREMOVALGRINDINGHIGHWELDINGSITEDIFFICULTTOIMPLEMENT1,1HAIR,2PROBESOFTHEWORKINGMODEL,ANDTHEREFORE,THESURFACEOFTHETESTFLATTHEINTEGRITYANDSMOOTHNESSREQUIREMENTSAREHIGHERTHANNORMALULTRASONICTESTING,OTHERWISE,ITWILLBEDIFFICULTTOMOVEPROBESORCAUSESIGNALLOSS412THEPROBESELECTIONISTODETERMINETHECENTERFREQUENCY,CHIPDIAMETER,ANDMAINSOUNDOFTHEPROBEBEAMANGLE4121CENTERFREQUENCY414PCSSELECTIONNONPARALLELSCANPCSISGENERALLYDETERMINEDACCORDINGTO11PCS4,DELTATANTHETA,3,INWHICHDELTAISTHEWORKPIECETHICKNESS,THETAISTHEMAINBEAMANGLETHATIS,THEBEAMAXISOFTHE2PROBESISDELIVEREDTOTHE2/3OFTHEWALLTHICKNESSOFTHEWORKPIECEWHENTHETHICKNESSOFTHEWORKPIECEISGREATERTHAN60MM,ITISDIVIDEDINTOSEVERALREGIONSINTHICKNESSDIRECTIONTODETECTZONEDETECTIONCANBEDONEBYUSINGMULTICHANNELDETECTIONEQUIPMENTATONETIMEASINGLECHANNELDETECTIONDEVICECANALSOBEUSED,ANDDIFFERENTPROBESAREUSEDFORMULTIPLESCANNINGINCREASINGTHEPROBEFREQUENCYCANIMPROVETHERESOLUTIONANDDEPTHDIRECTIONMEASUREMENTACCURACYOFTHEDEFECT,BUTTHEHIGHERTHEFREQUENCY,THESMALLERTHEDIFFUSIONANGLEUNDERTHESAMECHIPDIAMETER,THETHROUGHWAVEWILLOBVIOUSLYWEAKENOREVENDISAPPEAR,SOITISDIFFICULTTODOTHENEXTSCANNINGANDANALYSISINADDITION,THEFREQUENCYISTOOHIGH,THEATTENUATIONISLARGE,ANDITHASGREATINFLUENCEONTHEINSPECTIONOFTHEHEAVYWALLWORKPIECEBUTTHEFREQUENCYISTOOLOW,THEACCURACYANDRESOLUTIONARENOTUPTOTHEBASICREQUIREMENTSTHERECOMMENDEDFREQUENCYIS5MHZ4122WAFERDIAMETERATTHESAMEFREQUENCY,THESMALLERTHEDIAMETEROFTHECHIP,THEGREATERTHESPEEDOFSOUNDDIFFUSIONANGLE,BUTTHECHIPDIAMETERISTOOSMALL,THEEMISSIONENERGYISINSUFFICIENT,ANDTHEDIFFICULTYOFMANUFACTURINGISMOREDIFFICULTUNDERTHEEXISTINGEQUIPMENTANDPROBEMANUFACTURINGLEVELSOFTOFD,THISTESTRECOMMENDSAWAFERDIAMETEROF6MM415BEFORETHEMARKDETECTION,THESCANNINGPATHSHALLBEDETERMINEDANDGIVENONTHEWORKPIECETOBEINSPECTED4123ANGLEOFMAINBEAMIDENTIFICATION,INCLUDINGSCANNING,STARTINGPOINTANDSCANNINGDIRECTION,ETCTHEMAINBEAMANGLEOFTHEPROBEISUSUALLY45DEGREES,60DEGREES,70DEGREES,ANDTHEMAINBEAMANGLEISLARGE,PCSIS3INTHEFORMATIONOFLARGEPCSUNDERTHECONDITIONOFSCANNINGDISPLAY,DIRECTWAVEANDBOTTOMWAVERELATIVELYCLOSE,LOWRESOLUTION,DEPTHMEASUREMENTERROR,ANDTHEDIRECTWAVESIGNALISREDUCEDTHEMINIMUMPCSMAINBEAMANGLEIS45DEGREES,BUT,INTHEPRACTICALINSPECTION,THEPROBEWILLBECOVERWELDWIDTHRESTRICTIONSTHEREFORE,WHENTHEWORKPIECEWALLTHICKNESSIS12200MM,416WHENCOUPLINGAGENTSSELECTTHEACTUALTEST,THECOUPLINGUSEDSHOULDBECARRIEDOUTWITHTHESYSTEMWHENTHECOUPLINGAGENTISTHESAMEIFTHECOUPLINGISNOTGOOD,THESTRAIGHTWAVELWANDTHEBOTTOMREFLECTIONWAVEBWAREDIFFICULTTOFORMALINEARSHAPE,ANDTHECOUPLINGAGENTISTOOTHICKTOBEAPPLIED,ITMAYCAUSEWIDENINGOFTHEBLACKANDWHITESTRIPESINTHESCANNINGIMAGEANDINCREASETHEMEASUREMENTERRORFROMTHEEXPERIMENTALRESULTS,ITISDIFFICULTTOUSEPASTE,DETERGENT,OILANDOTHERCOUPLINGAGENTS,ITISBESTTOUSEADEDICATEDFINISHEDPRODUCTCOUPLINGAGENT70DEGREESPROBEASFARASPOSSIBLEUNLESSTHEPCSDISTANCEISLESSTHANTHEDETECTIONAREATHEWIDTHOFTHEDOMAINDOESNOTUSETHE60DEGREEPROBETHE45DEGREESPROBECANBEUSEDESPECIALLYWHENTHEWALLTHICKNESSISLARGETHE60DEGREEPROBEISMOSTCOMMONLYUSEDTOSUMUP,INTHETOFDDETECTIONOFWORKPIECETHICKNESSOF12200MM,THISTESTISRECOMMENDEDACCORDINGTOTHEPROBEPARAMETERSSHOWNINTABLE1TABLE1THICKNESSOFWORKPIECE/417COMBINATIONOFPROBEANDWEDGETOFDPROBESANDWEDGESAREUSUALLYORGANIZEDINTHEMANNEROFFIGURE6INCOMBINATION,ITISNECESSARYTOADDACOUPLINGBETWEENTHEPROBEANDWEDGEPREFERABLYASOLIDFORMOFMECHANICALBUTTER,BEFORECHANGINGDRYTHEPROBEMUSTBESCREWEDINPLACE,OTHERWISETHEULTRASONICBEAMWILLNOTBEABLETOEFFECTIVELYENTERTHEWORKPIECEPROBELINEJACKRECOMMENDEDSELECTIONANDSETTINGOFPROBESFORTOFDTESTINGOFPOWERPLANTEQUIPMENTSCANNINGNUMBER/DEPTHOFCORRESPONDINGDEVICEMMMMBEAMANGLE/SOUNDBEAMINTERSECTION/DEGMMFOURLARGEPIPES,HIGHPRESSUREPIPE,HIGHANDLOWVOLTAGEWITH1260HEATER,DEAERATOR,CONTAINERONE0T70602T/3LONGITUDINALWAVEPROBE60100THICKWALLPRESSUREPIPEANDSTEAMDRUMTWO0TOT/2,T/2TOT,0TOT/3,T/3TO2T/3,2T/3TOT70606045606045706045。2T35T62T95T98T/9探头楔块间添加耦合剂楔块（有机玻璃或类似材料）波束角度100200汽包三图6典型的TOFD探头与楔块的组合方式注T表示工件厚度。413扫查方式选择四点二基于OMNISCANMX检测仪的系统设置TOFD的扫查方式分为非平行扫查和平行扫查TOFD检测前，要最后完成对各种检测参数的三十六内蒙古电力技术2010年第28卷第6期设置（即系统设置）。本次试验只基于OMNISCANMX检测仪进行系统设置，见表2。五五点一特种试块的TOFD检测检测结果使用OMNISCANMX检测仪对试块的焊缝进行了非平行扫查，部分D扫描显示见图使用到7MOVIEWER软件对缺陷进行了测量，结果见表3。52数据分析通过TOFD检测，检出了试块内不同性质、不同方位的所有缺陷，缺陷成像直观、易于识别。在常规超声检测中难以检出的与探测面接近垂直的根部裂纹、侧壁未熔合等缺陷均被TOFD有效检出缺陷的成像特征随缺陷性质的不同而不同，FORSTRAIGHTWAVEFRONTANDTHEWAVEFORMDISPLAY,THISSHOULDREDUCETHEVALUEOFPRF,UNTILASHOWEDTHROUGHWAVEFRONTINTOLINEARINPRFTOOLOWSCANNINGSPEEDTOOFAST,SCANNINGSTEPISSETTOOSMALL,YOUMAYLOSEDATA,SUCHASTHEEMERGENCEOFABLACKLINEINTHEBDISPLAYIFOTHERFACTORSINTHEADJUSTMENTOFTHEDIRECTWAVEISSTILLVERYWEAK,NEEDTOREDUCETHEHIGHVALUE,AVOIDTHESPREADTOTHELOWFREQUENCYPARTOFFILTERSURFACEOFFTOFDINSPECTIONMUSTSETFULLWAVERECTIFIEDSIGNALAVERAGEMAXIMUMVALUEOFTHEGENERALELECTION,TOTHEGREATESTEXTENTTOELIMINATETHEINTERFERENCEOFNOISESIGNALBUTTHELARGERTHEAVERAGENUMBEROFSIGNALS,THESMALLERTHEMAXIMUMALLOWABLESCANSPEEDSUPPRESSIONOFAVERAGENUMBEROFFILTEREDDETECTIONSIGNALSQUALCOMMF/2LOWPASS2FFORFULLWAVERECTIFIERRFISSETTOTHEMAXIMUMVALUEOF16TO0GENERALLYSTRAIGHTWAVEAMPLITUDEISSETTOFULLSCREENHIGH4080STARTINGPOSITIONSHOULDBESETFORTHEDIRECTWAVEREACHESTHERECEIVINGPROBEBEFOREATLEAST1S,THEWIDTHOFTHEWINDOWTOTHEBOTTOMSURFACEOFTHEWORKPIECEINACONVERTEDWAVEAFTERWAVE1STABLETNOSUPPRESSIONWASDETECTEDINTOFDDIRECTSENSITIVITYSETTINGSONTHEWORKPIECE,IFTHEDIRECTWAVEISNOTSUITABLEORNOTVISIBLE,THEBOTTOMSURFACEOFTHEWAVEAMPLITUDEISSETTOFULLSCREENHEIGHT80,INCREASE2032DBTHESENSITIVITYISTOOLOW,MAYNOTBETHEDIRECTWAVEANDUNDETECTEDDEFECTSTHESENSITIVITYISTOOHIGH,ITMAYNOTBEABLETODIRECTLYMEASURETHEPEAKSETFORNONPARALLELSCANNINGOFWELDWORKPIECEINTHEBASEMATERIAL,VESSELSANDPIPINGWERETREATEDACCORDINGTOTHEFLATAANDBSCANRESULTSALSOSHOWEDTHATFACILITATETHEANALYSISANDMEASUREMENTONTHERESOLUTIONOFTHEENCODERINPUTRATING,THENECESSARYCALIBRATIONCANNOTBESELECTEDACCORDINGTOTHETIMETRIGGEREDSCANTODETERMINETHEACTUALDIRECTION,OTHERWISEITWILLNOTBEDONEWITHTHEDATACOLLECTIONONTHEWORKPIECEIDENTIFICATIONMATCHINGACCORDINGTOTHEQUASIPROBEWALKINGDISTANCESCANNINGSTEPSUCHASTOOSMALL,THENTHEDATAFORBYTEGEOMETRICSERIESINCREASESCANNINGSTEPSUCHASTOOMUCHINFORMATIONLOSSOFALARGENUMBEROFWELDSSENSITIVITYGAINASCANTIMEWINDOWWORKPIECEGEOMETRY,DISPLAYMODE,POSITION,ENCODERRESOLUTION,ENCODERPOLARITYTRIGGER,SCANSTART,SCANSTOP,DISTANCESCAN,STEPBYSTEPAB12,STEP/MMFORWARDORREVERSEENCODERTRIGGERING0MMSLIGHTLYLARGERTHANTHEDISTANCETRAVELEDBYTHEPROBE1MM,THATIS,THEENCODERTAKES1ASCANSAT1MMEACH2010VOLUMESIXTH,ISSUETWENTYEIGHTHTABLE3TESTBLOCKSERIALNUMBERINNERMONGOLIAELECTRICPOWERTECHNOLOGYTHIRTYSEVENMEASUREMENTRESULTSOFINTERNALDEFECTSOFSPECIALTESTBLOCKSBURIALDEPTH,/MMSELFHEIGHT,/MMDEFECTPROPERTY,SIDEWALLNONFUSION,CENTERLINECRACK,SLAGACCUMULATION,GASPOROSITY,NOPENETRATIONDEFECT,BLENGTH/MMDESIGNVALUE,MEASUREDVALUE,DESIGNVALUE,MEASUREDVALUE,DESIGNVALUE,MEASUREDVALUEDEFECTATOFDD1,TOFDD5,TOFDD6,TOFDD8,TOFDD918202017181918851084,37,63,6556363,66,54,76FIGURE10THEDIGGINGRESULTOFWELDDEFECTSONTHECYLINDEROFACONTINUOUSEXPANSIONDEVICETWENTYONETWENTYSEVENTHREEPOINTFIVESIXSEVENPOINTONESIXPOINTTHREEHIGHPRESSUREHEATERUSINGTOFDTECHNOLOGYHASONUNIT1,HUANINGPOWERPLANTGOLDAPPLICATIONOF6TOFDINNONDESTRUCTIVETESTINGOFPOWERPLANTEQUIPMENTSIXPOINTONETHEUSEOFTOFDTECHNOLOGYTOHUARUNPLATEGIRDERCANDETECTGOLDPLATEUNIT1POWERPLANTINTHEWEBBEAM,2PIECESOFBUTTWELDOFMAINGIRDER,FOUNDNOFUSION,POROSITYANDOTHERDEFECTSEXCEEDTHESTANDARDAFTERDIGGINGANDDIGGINGTHEDEFECTIVEPARTS,THEACTUALRESULTSAREINGOODAGREEMENTWITHTHETESTRESULTS,ASSHOWNINFIGURES8AND9THEHPHEATEROFNO2UNITOFMOUNTAINPOWERPLANTWASTESTEDANDNODEFECTSWEREFOUNDSEVENCONCLUSIONSANDRECOMMENDATIONS1TOFDDETECTIONCANDISPLAYTHEDEFECTIMAGEEASILYANDINTUITIVELYIDENTIFICATION,CANDETECTDEFECTSINANYDIRECTIONONTH