Remote Field Eddy Current Testing - International Nuclear Information .
KR0101218 KAERI/AR-593/2001 Remote Field Eddy Current Testing
2oooa " 2001. 3. 0
O Ofc J L CANDU gap - i -
SUMMARY Title : Remote Field Eddy Current Testing The state-of-art technology of the remote field eddy current, which is actively developed as an electromagnetic non-destructive testing tool for ferromagnetic tubes, is described. The historical background and recent R&D activities of remote-field eddy current technology are explained including the theoretical development of remote field approach, and eddy current, the results such as analytical and of analysis. finite element numerical The influencing factors for actual applications, such as the effect of frequency, magnetic permeability, receiving sensitivity, and difficulties of detection and classification of defects are also described. Finally, two examples of actual application, 1) the gap measurement between pressure tubes and calandria tube in CANDU reactor and, 2) the detection of defects in the ferromagnetic heat exchanger tubes, are described. The future research efforts are also included. - ii -
i 4 tfi* ol-E 3.1 3.2 t H f c) el - g * 3 Tiel - } * l - 4.1. 4 9 4.3 8 10 10 S - *o* 14 -T- %1- 3. . 14 7 UJ- Q tlT 1A W S % -i- Itl 71 4.3.1 3 . 5 tifl l 17 17 4.3.2 -ilSL e l 4.3.3 -fr A-ii -g- 17 23 Q7\*\% - ! § 5.1. 1 *Hd S3]5L3i- l o] . 5.2. Hl* -a. A-1 %7\ \ 5.3. #7iBl# A f 5.4 Tjel - Af i - l Sal JL2} o]§ 24 25 3L3\ O 1 tH* -8-* A4: S i 26 37 42 #«1 - 47 6.1. * -% &[ * 49 6.1.1. a}-g- s l - 49 6.1.2. zm l 7 l - 4 # JL216.1.3. 1 S.ofl rH*]: \if . 1 g*o* 51 51 6.1.4. q oH cfl« u 51 - iii -
7. ]# 7.1. & 55 7 ] e }*iW A oM- o] *]: ?% & aj q concentric tube } - 7.2. 55 7 3.%7\ a . 7 } # A f l . oj . 8. *l 58 - 61 8.1. 715L 1 61 8.2. -g-sf 61 - iv -
o. U s. xh Fig. 1. Diagram of pipeline inspection tool. 5 Fig. 2. Schematic showing location of remote-field zone in relation to exciter coil and direct coupling zone. 8 Fig. 3. Instantaneous field lines shown with log spacing that allows field lines to be seen in all regions. This spacing also emphasizes the difference between the near-field region and remote-field region in the pipe. The near-field region consists of the more closely spaced lines near the exciter coil in the pipe interior, and the remote-field region is the less dense region further away from the exciter. 9 Fig. 4. RFEC configuration with exciter coil and multiple sector receiver coils. 12 Fig. 5. Poynting vector field showing the direction of energy flow at any point in space. This more directly demonstrates that the direction of energy flow in the remote-field region in from the exterior to the interior of the pipe. 15 Fig. 6. Magnetic field lines generated by the exciter coil and currents in the pipe wall. The greater line density in the pipe closer to the outside wall in the remote-field region confirms the observation that field energy diffuses into the pipe interior from the exterior. A significant number of the field lines have been suppressed. 16 Fig. 7. Signal processing of impedance-plane sensor voltage in RFEC testing, (a) RFEC scan with a Br probes through a carbon steel tube with outside surface pits that were 30, 50, and 10% of wall thickness depth. Each graduation in x and y direction is 10V. (b) Horizontal channel at 0 rotation, (c) Vertical channel at 0 rotation. Signal amplitudes in both (b) and (c) are in arbitrary units. Only 70% flaw stands out clearly. 19 - v-
Fig. 8. Horizontal (a) and vertical (b) data of Fig. 7 after 100 rotation. Signal amplitudes are in arbitrary units. 20 Fig. 9. Data from Fig. 8 processed with the correlation technique. All three flaws are now well defined. Signal amplitude is in arbitrary units. 22 Fig. 10. Phase lag of detector signal with thickness: (a) experimental, (b) finite element simulation. 27 Fig. 11. Comparison of phase lag-frequency relationship from finite element and skin-effect predictions. 28 Fig. 12. Schematic of the remote-field eddy current device with an array of small receive coils in the remote-field region. The region with the proposed localized eddy current in the vicinity of the transmit coil is shown. 30 Fig. 13. Equivalent circuit model representing the transmit coil linked inductively with the pressure tube. The primary circuit represents the transmit coil in series with a resistor. The secondary circuit represents the section of tube in the vicinity of the transmit coil in which most of the eddy current flruiro — — - . Fig. 14. One-dimension example for the finite element model. *iO 41 Fig. 15. Wall of a conducting cylinder showing the incident waves (I) is partially reflected and partly transmitted at each air-metal interface. 42 Fig. 16. Change in phase of field after transit through a conductor. - 45 Fig. 17. Amplitude attenuation factors of field after transit through the tube wall in the field zone. Effective wall thickness was varied by changing the permeability, radii, frequency, or conductivity from the standard sample. 46 Fig. 18. Breadboard instrumentation necessary to excite and receive the 45-Hz signal. Analysis was based on the phase different between the reference and received signals. Fig. 19. Relationship between maximum probe speed and tube wall - vi - 48
thickness for normal assumptions of resolution and tube characteristics. 50 Fig. 20. Schematic of remote-field eddy current probe showing energy 4- 1 y—in? v o " r\Ci - . . . . . — -*w , . Fig. 21. Pipe with aluminum target with axial slot. O 53 Fig. 22. Radial magnetic field coil amplitude and phase changes for axial and circumferential 50 % deep cracks with various widths. 54 Fig. 23. Gap measurement between two concentric tubes in a nuclear fuel channel with an RFEC probe, (a) Cross-sectional view of probe and test sample. Dimensions given in mm. (b) Plot of eddy current signals illustrating effect of gap, wall thickness, and lift-off, (c) Plot of y-component of signal versus gap at a frequency of 3 kHz. 57 Fig. 24. Schematic representation of remote-field probe with dual receiver coils. 60 - vii -
Table 1. Comparison between test results and visual inspection of four tubed pulled from a feedwater heater. - viii - 59
1. (remote field eddy current inspection) * 1951 MacLean *] 4 ? H %*}i } # # *1 elfS. 40 S 2 tif) o . pitting [l]. [2], - 3 7}X] « o S 7 } SJt - . - 3 7}*1 ig S && % 1 1 3.71 4171 e l - l 2.
(support plate)5 (fill factor) Y S Hf'tHH 7} - 37)1 \ Hall *** 3. Pit, crack, 7} # ufi a# # 4 - s j u m sacf. pit corrosion J fe erosion Hl 4. #eH j - A - l J9L lxl- *}u}oj fill-factor lift-off JL:ZH tfl 0 -0.5.7} a t , dirts, scale -§ 1 I S -2 -
5. through-transmission mode *** 2. 3. 4. g*oMl o]3} go] 71 -3-
2 . 9i AH*l UH [3,4] 1951Vi a ] H H W. R. McLean ] 51: McLean 2573799)# # &- 1957 d 6fl nl -Sl Shell DevelopmentAHlA-j Schmidt 7} *}- casing pipe, o ] I960 A] :2* (oil-well 178-203 mm, 1 9.5-12.5 mm, [5]. % H f e far field -n-4 -8- HAf § - * W ? J - 5 ) j M remote field 3l2fe -3. - - .7f] Fig. lafl . c . a] A)7 ofl Shell A}CH) fltHrH "Ferrog" 1970 7} « q * H 1978 - -El #7\Z\% 3 L 4 *H7fl »! AJ , 71 51 1 tfl a »i*fl fe c-l] HS 4 5 ] 1.8 af - 4 -
Amplifier t Trig Strobe Strob* light firing in synchronism with pfcfcup signal. Ungtti of light unro«*k«d is measure of sfi« tf m« ««lay Exciter Coil Pickup Film Drive Motor J Syne. Motor v HeUx tplningin with cxciitr signal \ Inverter Battery 24v dc Fig. 1. Diagram of pipeline inspection tool. 1.8 aH u] Colorado Queens cf. n] - 7 , Southwest Research Institute(SwRI), TIMKEN A } , ?Jj Cyberscope A} - 1 1 nl- 7 l - 1 nm, Colorado , Fort Collinsofl Colorado 7 cflsfl meshl(potential v a l l y ) " } - 5 -
1986 1 BM-cf, Queens cfl (Kingston, Ontario, Canada) ] Applied Magnetics Southwest Research Institute(San Antonio, Texas, CyberscopeAj-(Edmonton, Alberta, Canada, 1986 Si) l'Mfe- Shell segmented detectorl- t n1- 1 - 4 groove7 groove u vfl groove S- ofl tflsfl H 50.8 mm, 3j 7 1 3.8 mm [6]. Russell TechnologiesA} ] s nff*f Ferroscope ef Hj7f 7f\1}Q Hf l Zetec, Testex - H14 c } # A]Bf5]Jl j a . ?} ufi:f5] CANDU 7 7fl 5l U} ojt:}. aMl l ?B n Sl Queens c f l l f e 7 C P S f ( 36 -7} #*J ]J! C} [5]. i (Stress Corrosion Cracking) - 6-
notch uf ] IU-Jin H o ol ofl cfl*B ?l J 7f V J i - f cracky [8]. 7 ] S # * 7] flafl 2000 12 *fl ASTM E-2096-00, "Standard Practice for In-Situ Examination 0 Ferromagnetic Heat-Exchanger Tubes Using Remote Field Testing" -rr" ] m. - 7- of
o 3. 0.6 - 1.0 Fig. }fe t: Fig. 3 [1], j 7ZZZZZZZZZ2ZZZZZZZZZZZZZZZZZZ2Z Z2ZZZZZZZZZZZZ22Z222ZZ2& t ] „"„, 1 Tube O D I f 17C1 Direct Tube ID coupling zone Exciter coil fS Remote field zone Detector array Fig. 2. Schematic showing location of remote-field zone in relation to exciter coil and direct coupling zone. -8 -
Inner wall Pipe axis 0.5 - . Excitercoil Radial position, multiples of coil radii Outer wait Pipe Fig. 3. Instantaneous field lines shown with log spacing that allows field lines to be seen in all regions. This spacing also emphasizes the difference between the near-field region and remote-field region in the pipe. The near-field region consists of the more closely spaced lines near the exciter coil in the pipe interior, and the remote-field region is the less dense region further away from the exciter. -9 -
3.1 direct coupling 5 l 2 f # *H&* fe shielding . S o ] 0 ! o}% - n]-*j cut-off 10 tifl §H *}c]. S ]i . -t!3lfe direct coupling 3} remote field coupling 2\ - 1 fr fl*}*! fe } [9]. o] ] )7f direct - remote coupling 7]] c ] t: . 3g 71 elcHl 0 - 1.8 «fl 1.8 ] f l i j i % } 7]S] 3.2. 10 ] }
3. i } # ) »3*M *\*} - Fig. - 11 *}7}5. Qv}. Schmidt [9]
Pipe wall Pipe axis Multiple sector receiver colls Exciter coll Fig. 4. RFEC configuration with exciter coil and multiple sector receiver coils. - 12 -
7} 2) . Rock-in amplifieri- V8* S Si- - -4IJE. 3) 1- 3 fe pitting - 13 -
4. s 4.1. [10-13]. fe 11 t oflS Fig. 5 ofl J ] Poynting vector Fig.6 4.2. 3 } 3E. 1 H W nl-AV7]-xlolt:l-. Fisher and et al. 2 } J * H X ) i T J I - A i 7 i l # - g - * } pitting unperturbed-field ] # f »} X \. - } [11]. - 14 - 2
Inner watl s. Outer wall / / / / / s *-*/// ss \W\\\ 3 1.0 / Radial position, muhipfes of coil radii \ 1.S Fig. 5. Poynting vector field showing the direction of energy flow at any point in space. This more directly demonstrates that the direction of energy flow in the remote-field region in from the exterior to the interior of the pipe. - 15 -
Inner wall Outer wall 1.4 I.S Radial position, multiples of coil radii Fig. 6. Magnetic field lines generated by the exciter coil and currents in the pipe wall. The greater line density in the pipe closer to the outside wall in the remote-field region confirms the observation that field diffuses energy into the pipe interior from the exterior. A significant number of the field lines have been suppressed. - 16 -
4.3. 4.3.1. - -Aiofl *]* p i t t i n g - - *1 # l * 7 l l«flA- unperturbed Fig. 6 unperturbed fi unperturbed field fl tfls} perturbation -S. unperturbed S pitting 6) cfl*B B r unperturbed field# 4.3.2. - 17 -
S.S. Stl K Fig. 7 3} 8 -* 70% 3096, 50%, Br pit- Fig. 8 olMfe- Fig. 7 ioo - 18 -
I 1 i 1 f ) Fig. 7. Signal processing of impedance-plane sensor voltage in RFEC testing, (a) RFEC scan with a Br probes through a carbon steel tube with outside surface pits that were 30, 50, and 70% of wall thickness depth. Each graduation in x and y direction is 10V. (b) Horizontal channel at 0 rotation, (c) Vertical channel at 0 rotation. Signal amplitudes in both (b) and (c) are in arbitrary units. Only 70% flaw stands out clearly. - 19 -
3.54E 00 3.aBE -QQi Fig. 8. Horizontal (a) and vertical (b) data of Fig. 7 after 100c rotation. Signal amplitudes are in arbitrary units. - 20 -
ZL»H pattern matching o]-g-*l -*13 f5l 7]*Qo] 7} }r}. Br #-§ U- } convolving 5 ] Fig. 9 fl pattern matching 3q 6fl cH«H iL Jofl cj # correlation algorithm # - g - 2 } 3 1 rjj u ] 7 f a fl % 5]fe l 3 } § a median filtering sj[t: [14]. - 21
I.85E4-Q1 1 0.00EH-00 13 .2 26 . 4 3 3 .k ft . i 5 - S 6! Fig. 9. Data from Fig. 8 processed with the correlation technique. All three flaws are now well defined. Signal amplitude is in arbitrary units. - 22 -
4.3.3. Atherton and et. al. [15] shielded plated 3-4 »1 olH 3 ] 5 3 «H1 1.5 M shield plateS * l * f e H v o l * } Infolytica A »] "Magnet" package # oj § o) xj o] ! 5 yflofl l.O «HS # H H 3 t S &i:f [15] ferrite - 23 -
o 5. (1) D (2) 471 20 - 200 N cos exp —5 exp % . 2 lift-off, - 24 -
5.1. [16] 71 (4) d d ic loss) 45 S. trfef vp 2 x / 8 (5) - 25 -
cflsf Fig. 10 dfl ig. I D 5.2. B(z,t) B ' magnetic flux density Bo: surface magnetic flux density t ' time §—{2plo fj)112- eddy current co ' angular p ' resistivity H ' magnetic skin frequency of tube material permeability - 26 - depth
0 / 330 300 / S70 (ft 2*0 UJ UI EC - -U) / a ui TSO CD .30 : SO / 30 -' 1 0 1 t 2 ! 3 1 ». 1 J t » 1 7 t 8 1 9 tO Pipe WALL THICKNESS mm A W. LORD UNITE ELEMENT DATA SKIM EFFECT EQUATION Sid X 360 : p 70 i 15 MICRO OHm «m / nr a / 170 180 90 0 S 10 15 23 35 30 WAU. THICKNESS mm B Fig. 10. Phase lag of detector signal with thickness: (a) experimental, (b) finite element simulation. - 27 -
X 4JJ0 - - W. LOftD FINITE ELEWEHT 0 * T » SKIrt CFFECTeoUATtCK j» 7O p 15 micro Onrn.c* Ul. -I 240 I X - 1 1 40- f «o 1 so 1 TOO i 120 EXCITATION FBEQUEWCV .1 T-ia leo Hz Fig. 11. Comparison of phase lag-frequency relationship from finite element and skin-effect predictions. - 28 -
[is] Biot-Savart -0 ' permitivity law of free space fx0 ' permeability of free space co ' angular frequency of probe signal a ' conductivity of tube material Jn nth-order Bessel function Nn ' nth-order Neumann function In nth-order modified function of the first kind Kn ' nth-order modified function of the second kind Fig. 12 } } »H1 cfl V 7 } S S : Fig. 13 2 , , ,2 r 2 - 29 "
Point locattud tfrfy current l N Fig. 12. Schematic of the remote-field eddy current device with an array of small receive coils in the remote-field region. The region with the proposed localized eddy current in the vicinity of the transmit coil is shown. - 30 -
Secoattary Circuit Primary Circuit Fig. 13. Equivalent circuit model representing the transmit coil linked inductively with the pressure tube. The primary circuit represents the transmit coil in series with a resistor, The secondary circuit represents the section of tube in the vicinity of the transmit coil in which most of the eddy current flows.
Rz. Lz fe t f § fe l Rz 4 -5.S. r d f e Grover reference M {LxL2)m K (9) 0 K 1, K fe -g-J r source JLJL Biot-savart point magnetic dipole 3. dipole S.3. m2 source magnetic moment, 3. & r fi] magnetic dipole moment &} nfl, (11) /2 (12) - 32 -
(13) 4 (14)S (15) (16) Talor - . (17) Z\ (18) (19) 3.5/ (20) - 33 -
time-harmonic - dHr dz (21) 0 dHz oEcfr dz (22) (23) dr &* (24) (21) - (24)13Hr Hr # r r z - S - (26) Hr - (27) 0 (28) 34 - (20)
(29) . 0 b2Kx(ar)] 2 a x e a,a,1"** (30) (31) j (21) - (24) HI ni (29), ( 3 0 ) - (0 r HXr,z,t) (32) Hx{r,z,i) (33) - -. (0 Hr(r,z,f) Hz{r,z,t) - f a2 (34) (35) [ (r 2 r) c2Nx(kr)} - 35 - (36)
Hlr,z,t) r z 0 H [cJoifcr) c2N0(kr)] (37) 2. - (38) Hr , clt c2 # 4 4 «i, bu b2, 5 7fl r i?, Hr & r rlt Fig. 12 r r2 (36) XJ( 37 ) 5.3. [20-23]7} [20]. Maxwell-Ampere, Maxwell-Faraday fe cfl Maxwell J H dl j jg } ds (39) J (40) - 36 -
B (41) MH / aE (42) U 0 JJ[ B ds 0 (43) J /ds 0 (43) magnetic vector potential A -fe B curl A (44) vxA (44) # curl i1- curt A) / r - (45) t o -f, OCy.d a (1/A 7)1/2 O ) (46) /(3 ,# fe - 1 S i H, E, J, S magnetic vector potential A -g- ] .O) Av) 37 - c r I } . ] \ 1 JC L * ] 3L7\
lXy,t) (47) n l (48) A Chateau [24] (49) (47) - (49) fe ,Q) Ay) (46)5 Fig. 14 ofl i l H o j y o a SI (x-z )6fl H(y,cot) HQ exp(-py) p (50) cos (cot-py) -i- (l) 7] ] - 38 -
(2) (3) interference 39
(T» Q Fig. 14 One-dimension element model. example - 40 - for the finite
5.4. Mackintosh and et al Fig. 15 [25]. Pipe wall Fig. 15. Wall of a conducting cylinder showing the incident waves (I) is partially reflected and partly transmitted at each air-metal interface. S Y XI8, S.5. o oU A vector potential ArHJ2\kp)] - 41 - for p rQ (51)
for ri p r0 for p i n S-. -7] 5J 5 magnetic vector p o t e n t i a l 4 4 " 1 m Bessel S 1 s (53) if , * S. efl i U4 field, field, (52) / 2 } field, & ulf A-] «VA} field, f i e l d # t c . a* H fe Hankel } (wave number) -fe-, — jcoGix (54) vector potential A \ 'cJ-S Rr scalar potential V -1 "T-UzT 0 V fe, (55) (56) 4 7 ] -frSLfe, (57) - 42 - e
H S kro l 91 krt l o]v\ Bessel t K * Hankel f e , r r. 2 j: sinii:r (Krfofir) cosier] r fe VcosM2r)-cos(2y) (59) radian I (60) 7 0 »fl -5 ifr 7} - f *1 (58) fe Figs. 16 17 3} cK - 43
(f) XJ 0. co -5 -1.0O *co -1.5 .Skin depth theory -\ % CO s -20 o \ x — — E p«fimeotal-fiiwalpipe xperim«Ttal-hatfwalpip« Thfougb-transufe on aquation \ \ V V - -2.5 V 2 Wall thickness in skin depths Fig. 16. Change in phase of field after transit through a conductor. - 44 -
;Skin depth theory o CO o CO co .01 a .pernieabity r0 - Outside rad radus o .001 r, - hade radius v « f.- frequency; c - conductivity Pants: Dodd and Deeds analytical caioJafons Sojki Spas: RFECtivou vtfanafwsain fe .0001 , Wall thickness in skin depths Fig. 17. Amplitude attenuation factors of field after transit through the tube wall in the field zone. Effective wall thickness was varied by changing the permeability, radii, frequency, or conductivity from the standard sample. - 45 -
6. fe Fig. 18 6j 1) 1 5 . ] (Oscillator J fe Function Generator), 2) g 7l (power amplifier, U*l«g-.2.3. ?i 3) *]7] (phase and amplitude detector), 4) detector 3 . - " cfldl 5l* 7] 4\ \; PC, 5) 1 3 2 } r lS a# 5 J*fe } chart recorder) 3. MS] *\3L7\ nfl-f *}7l irH ofl lock-in amplifier 4 - 8 Ohm a)3. - 46 - 7l- - Hl(ofl: strip
Phase detector Strip chart output Reference Oscilloscope Signal generator Power amplifier Lock-in amplifier Average total wall thickness probe Type 1 Exciter Spot wail thickness measurement Sensor Type 2 Fig. 18. Breadboard instrumentation necessary to excite and receive the 45-Hz signal. Analysis was based on the phase different between the reference and received signals. - 47 -
6.1. 6.1.2. . t# §«H mm, - 50 3.6mm (0.14 inch) 40 Hz7}* v ] 7 H 61 cycled « 1 r J l H S 3J% 2.5 mm(0.1 inch) v\t\ 40 iq Hl &r}. n n{j - r S c S cfl QX[ - 102 mm/s ( 4 inch/s) S.-fe- 6m/min (20 7) «H4fe . 7 c l Xl}M. %O)V\.) [l]. - 48 - Fig. 19
Tube wall thickness, in. 0.098 0.196 0.295 0594 0.492 25 5.0 7.5 .10.0 Tube wall thickness, mm Fig. 19. Relationship between maximum probe speed and tube wall thickness for normal assumptions of resolution and tube characteristics. - 49 -
6.1.3. l o.u} o] 6.1.4. tubesheet7 7) fin 6.1.5. A t h e r t o n e t . a l . [26] 711 9 . 5 / - 0 . 5 mm, 2% Mn 70, S 6. 7 X 10 6 - 50 - 508 mm,
440 mm ofit:} AWG No. 20 wire-H 200«i 3]- 25 mm gap § -f}-*l*}fe 1**1 a - g - A-rms/turn# A n } #7]Z}% 'gTfl'Srfca. 7 H *Hf- g *Hl M d t e AWG No. 44 wire # 2 0. 5 mm, 3} ! 17 0.5 mm, z]o 10 0.5 mm 3.7]6\}r\ 0.7 ifl 20,000 «1 J K Fig. 20 »fl Ji*I H o ) Bobbin coil al} 251 jaw, 508 pm, 813 fim & § . S 0 (Fig. 21). Fig. 22 *fl 2t*l H ) W 1 ao o* ! H 4 'g c) - 51 -
INDIRECT ENERGY FLOW PATH r * 1 1 ! — DETECTOR COIL DIRECT ENt RCY FLOW PATH EXCITER COIL % DIRECT COUPLING ZONE. TRANSITION' 2ONC 1 1 1 1 REMOTE H E L D 2DNE 1 PIPE WALL i Fig. 20. Schematic of remote-field eddy current probe showing energy flow paths. AXIAL SLDT. ALUMINUr-t TARGET- Fig. 21. Pipe with aluminum target with axial slot. 52
AXIAL CRACK 7.O0-O3 V - 251pm 502}imi 813pm 6.00-03 V i X 5.00-03 V OKCUMFEBENILM, CRACK 7.00-03 V - - S13 xja i 6.00-03 V - i 1502ixm i 1 AA I I ! ! 25I im ! ! ' S.0OO3 V AV i 4.00-03 V 1I i - 4.00-O3 V - 3.00-03 V vl 1 i 3.00-03 V 1 1 i 3S0OTOO AJ AMPIJTUDE 15 20 - t 20* - - 19* i 10" J S* (\ \ \ J 0/ -5 10 V - J W V A - 6* - 0* -V - Ii i 10" - - 15* - —TV V L v V - 20» 20» i i B) PHASE Fig. 22. Radial magnetic field coil amplitude and phase changes for axial and circumferential 50 % deep cracks with various widths. - 53 -
7. 7.1. ?]eR - - - o §-t channel concentric tube CANDU i 5 ] S.fe cflaf 6 m 7} 7 alt:}. 6] *m#2} tfl Bl m o]x]* o t c}. ol-i- .)sl] o j - . tl*H5 o}2i 4 l f e garter spring spacer 7} 7 l * SlAv]- d } 7]- ol] tcfe spacer*} \*\7\ l l n: e i - 3 - M creep Q Q * ;g (sagging) ] t garter sping ] gap § gap ofl r C02 71 7} - j SLS.JL 3X7} . Af .5. tube # s 4.2 mm o]n Zr-2% Nb - g - S . 7 1 . 520 nQ O)B.S. 10 kHz o ) 100 mm o ] « . S # 1 3 . o ] mm o l o ] o : *y . cfl A 6fl 150 mm S. *l«- Si . o] 0.01% 3 . - A l n j t ; } [ 2 7 ] . - 54 - 100
cross-talk phase-sensitive detector (lock-in amplifier) fl A/D converter # 7 PC S. plot Fig. 23 (a) 6 gap 13 mm 7) el 7} Stl -t H e W S j 10mm ) o * } j q 7 ] x-l o] 3 2 ZL - } S? g 7] j U 4 # V § * f e Cfl 7lA gap * Lift-off * Pressure tube ] .7] * Pressure gap gap, *fl, 7l % , lift-off 313} l i i lift-off } gap h!3l#5} 90 S. 3 - 4 kHz S. l gap, lift-off, Fig. % 71] 'ilJL S f # Fig. 23 (b) 23 (c)6 - 55 -
1.6 Zircaloy-2 calandria tube Gap I JLL X » 4.2 Zirconium-niobium pressure tube Receive coil Transmit coil RFEC probe 103.4 -75- Gap Gap, in. 0.12 0.24 035 0.47 0.59 0.71 1.4 17- 1.2 / 151.0 12- / 0 8 i - Gap. mm / / E 8 0.6 ]/ 0.4 y 0.2 / / 11% 6 Lift-off ib) 9 Gap, 12 15 18 mm (c) Fig. 23. Gap measurement between two concentric tubes in a nuclear fuel channel with an RFEC probe, (a) Cross-sectional view of probe and test sample. Dimensions given in mm. (b) Plot of eddy current signals illustrating effect of gap, wall thickness, and lift-off, (c) Plot of y-component of signal versus gap at a frequency of 3 kHz. - 56
ojofl * ] 2 : 2 } } # 'S*]*M # * I * M o]5j* B * assembly .*! gap 0 - 18 mm HH 1 mm n J 7.2. Echoram 4 1 t VA 7l6fl -S- l ? -# * H 3J M# -% o # -§- 1 ASCIS (Advanced Carbon Steel Inspection System) # 7fl* j-5J- 5lt:} [28]. 7] : . . ASCIS l l J- l 1 (Zetec *} ] MIS-18) 3 interface 7f 7} %-*M X-Y H J * H H lissajous IS-S. # Sic*. u.# 4* 7] 1 U S Hall effect 51 Hall effect 3.7]7\ 51*}7J S. 4 * f l 5 1 % 3 1 # *fe 7 ) # ASCIS j a # lJcolH. S a -% . l l .ai - Ji g A ] , A/D converter, HP 9836 computer, digital cartridge tape recorder -§-.3. 51 iS ASCIS u n i t # 2f Table 1 dfl - 57 -
Table 1. Comparison between test resules and visual inspection of four tubed pulled from a feedwater heater. 1 1 1 6 6 6 2 2 7 7 7 !Actual Maximum Actual Gross Depth {%) ; Defect Depth Wall Depth {%) i (*) 89 . , 30 go 92 75 100 50 89 90 82 25 52 62 30 62 5 29 25 64 48 50 46 40 5 i 80 ' 30 67 77 i 25 63 30 42 1 iq Fig. 22 Fig. 24 - 58 -
Transltioa Zone Efeect CaapIingJZtga I- Indirect Coupling Remote Reld-Zone y .- :7——-.--ZZ.z :r--.---.-jzJi-.\ sV&Mr' f f t f "II LL -v ) /III ( I I I \ Dkect Coupling iii/ifnm/iuuiiwmiitiirm— * Exciter Coil ID Receiver Coil- Receiver Coil Fig. 24. Schematic representation of remote-field probe with dual receiver coils. - 59 -
8. 8.1. Maxwell 8.2. y-g-Sf 3.71 %3 #n*\ 7\% A« 4 % 4 life} 1 , Sfl- - 60 - -iTfloH 01 4
- 61 -
1. J. L. Fisher, Metals Handbook, 9th ed., Vol. 17, ppl95-201, ASM International (1989) 2. K. Krzywosz, L. Cagle, "Comparison of three electrmagnetic NDE procedures using realistic feedwater heater mock-ups", Mater. Eval. (1993) 132-139. 3. Y. shindo, T. Yamagishi, and H. Hoshikawa, "The trend of Remote Field Eddy Current Technique in the World, «H H]s]-;z] J ;x]( 39 (l)(2Pfig 2 IE, 1990) 19-25. 4. T. R. Schmidt, "History of the Remote-Field Eddy Current Inspection Technique", Mater. Eval., 47, (Jan. 1989) 14-22. 5. T. R. Schmidt,"Instrument Promises to permit Measuring Wall Thickness of Pipelines in Place", Mater. Eval., 2 (1) (1963) 8-12. 6. T. Kukuta, T. Yamaguchi, Y. Hosohara, and K. Yasui, "A remote field eddy current inspection system for small-diameter steel pipes", Proc. 12th WCNDT, Netherlands, (1989) Eds. J. Boogaard and G. M. Van Dijk, Elservier, 946-949. 7. ASTM e-2096-00 "Standard Practive for In-Situ Examination of Ferromagnetic Heat-Exchanger Tubes Using Remote Field Testing", 8. J. B. Nestleroth, "The remote field eddy current technique for stress corrosion crack detection and identification", Brithsh J. NDT, 35 (5) (1993) 241-246. 9. T. R. Schmidt, The remote field eddy current inspection technique, Mater. Eval., 42 (1984) 225-230. 10. J. L. Fisher, S. T. Cain, and R. E. Beissner, "Remote Field Eddy current Model", in Proc. 16th Symp. on Nondestructive Evaluation (San Antonio, Tx), Nondestructive Testing Information Analysis Center (1987). 11. W. Lord, Y. S. Sun, and S. S. Upta, Physics of the Remote Field Eddy - 62 -
Current Effect, in Reviews of Progress in Quantitative NDE, Plenum Press, (1987). 12. D. L. Atherton and S. sullivan, The Remote-Field Through-Wall Electromagnetic Technique for Pressure Tubes, Mater. Eval., 44 (Dec 1986) 1544-1550. 13. S. Palanisamy, in Reviews of Progress in Quantitative NDE, Plenum Press (1987) 14. R. J. Kilgore and S. Ramchandran, "Remote Field Eddy Current Testing of Small Diameter Carbon Steel Tubes", Mater. Eval., 47 (Jan 1989) 32-36. 15. D. L. Atherton, W. Czura, and T. R. Schmidt, Mater. Eval., 47 (1989) 1084-1088. 16. T. R. Schmidt, One-Dimensional Characteristics, D. L. Atherton, and S. Sullivan, "Use of Skin Effect Equations for Predicting Remote-Field Including Wall Thickness versus Frequency Requirements", Mater. Eval., 47 (1989) 76-79. 17. S. Sullivan and D. L. Atherton, "Analysis of the Remote-Field Eddy Current Effect in Nonmagnetic Tubes:, Mater. Eval., 47 (1989) 80-86. 18. Dodd, C. V. and ffi. E. Deeds, "Analytical solutions to Eddy Current Probe-Coil Problems:, J Appl. Phys., 39 (1968) 2829-2838. 19. Grover, F. W. , Inductance Calculations : Working Formulas and Tables, 1962, Dover, New York, NY. 20. Y. S. Sun,"Finite Element Study of Diffusion Energy Flow in Low-Frequency Eddy Current Fields", Mater. Eval., Vol. 47 (1989) 87-92. 21. D. L. Atherton and W. Czura,"Finite element calculations for eddy current interactions with collimear slots", Mater. Eval. (1994) 96-100. 22. E. von Rosen and D. L. Atherton, "Effect of shielding and exciter coil tilt on the remote-field effect", Mater. Eval. (1993) 66-71. 23. D. L. Atherton, T. R. Schmidt, T. Svendson, and E. von Rosen," Effects of remote-field exciter coil tilt and eccentricity in a steel pipe", Mater. Eval. (1992) 44-50. - 63 -
24. Du Chateau, P. C. , Applied Partial Differential Equations, 1988, Harper and Row, new York, NY. 25. D. D. Mackintosh, D. L. Atherton, R. A. Puhach, "Through-transmission equations for remote-field eddy current inspection of small-bore ferromagnetic tubes", Mater. Eval. (1993) 744-748. 26. D. L. Atherton 0. Kink, and T. R. Schmidt, "Remote-Field Eddy Current Response to Axial and Circumferential Slots in Ferromagnetic Pipe", Mater. Eval., (1991) 356-360. 27. D. L. Atherton, S. Sullivan and M. Daly, "A Remote-Field Eddy Current Tool for Inspecting Nuclear Reactor Pressure Tubes", British J. NDT, (Jan. 1988) 22-27. 28. D. J. Brown, Q. V. Le, "Application of Remote-field Eddy Current Technique to the In-Service Inspection of Ferromagnetic Heat-Exchanger tubing", Mater. Eval., 47 (Jan. 19889) 47-55. - 64 -
INIS Afls * * * * * * * KAERI/AR-593/2001 " "§" "T" (41 1" S *r *1 * A] )» o - -AT- fsflo c - - - - - - - 2001 sfl c] 1 64 p. § 711 ( 0 ) , v--El yr JX. lyl( ), XI-S-C o ), §! §-( ) 3 71 Cm. «*) * 2:-It (15-20#i-(l&]) r Mfl ufl s 7-r 7 l r % i l tflsfl Et- l nl x o1 1 j4-o]i c ] cf 3 lA-l S z\sL fl s l gap -s " V J "eJB- t7l # 2 - t -Bill- I r x i - « :§: n - 3j- oll tflsllA 7 l l - l ' Remote Field Eddy Current Testing (RFECT), Elec:tromagnetic Nondestructive Testing, Finite Channel, Ferromagnetic Inspection. Element Model, CA NDU Fuel
BIBLIOGRAPHIC INFORMATION Performing Org. Sponsoring Org. Report No. Report No. SHEET Stamdard Report No. INIS Subject Code KAERI/AR-593/2001 Title / Subtitle Remote Field Eddy Current Testing Project Manager Y. M. Cheong(Nuclcar Materials Technology) and Department Researcher and H. K. Jung (Robotics Lab.), H. Huh (Power Reactor Tech.), Department Y. S. Lee (Nuclear Fuel Fabrication Tech.), C. M. Shim (HANARO) Publication Taejon Publisher Publication KAERI Place 2001 Date Page 111. & Tab. p. 65 Yes( o), No ( ) Size Cm. Note Classified Open( o ),
Fig. 2. Schematic showing location of remote-field zone in relation to exciter coil and direct coupling zone. 8 Fig. 3. Instantaneous field lines shown with log spacing that allows field lines to be seen in all regions. This spacing also emphasizes the difference between the near-field region and remote-field region in the pipe. The near-field
EC Eddy Current ECPT Eddy Current Pulsed Thermography ECT Eddy Current Testing EM Electromagnetic EMAT Electromagnetic Acoustic Transducer EMF Electromagnetic Field GMR Giant Magnetoresistance GPIB General Purpose Interface Bus GPR Ground Penetrating Radar IR Infra-Red LPT Line Printer Terminal MFEC Multi-Frequency Eddy Current
Search on eddy current braking on google lIgnore links to: u Mary Baker Eddy u Fish's Eddy lIn addition to these generator brakes, the braking function of the vehicle is assured by the modular eddy-current brakes. The individual eddy-current braking magnets act on the guidance rails of the guideway and guarantee the braking of the vehicle.
Eddy Current Probes Olympus eddy current probes consist of the acquired brands of Nortec and NDT Engineering. We offer more than 10,000 stan-dard and custom designed eddy current probes, standard refer-ences, and accessories. This catalog features many of the standard design probes
The eddy current brake implements the idea introduced above to generate a torque sufficiently large that resists the rotational motion of wheels. Figure 2 shows the schematic diagram of a simple eddy current brake with only one magnet around it. The subsequent analysis is based on this simple model. Figure 2: Schematic diagram of eddy current .
of the non-destructive remote field eddy current testing method appeared about 30 years ago. This method allows to significantly expand the field of application of eddy current testing. However, due to the lack of a theo-retical justification, this method did not get widespread use around the world. Domestic publications in this area
Eddy Current Test Ing. Herbert Baumgartner, CEO & Owner of ibg NDT-Group page 1 of 10 04.Dec.2012 Handbook Induction Heating Eddy Current Paper.doc Both induction heating and eddy current testing work with coils, generators, ac-current and ac-voltage, frequencies, field strength and induction law.
THE REMOTE FIELD EDDY CURRENT TECHNIQUE The remote field eddy current (RFEC) technique was patented by W. R. McLean (US Patent 2,573,799, "Apparatus for Magnetically Measuring Thickness of Ferrous Pipe", Nov.6, 1951) and first developed by Tom Schmidt at Shell for down hole inspection (Schmidt, T. R., "The Casing Instrument Tool- ",
Keywords Non-destructive testing Pulsed eddy currents Material characterization Structural integrity Non-destructive evaluation 1 Introduction Despite its approximately-five-decade-long history, PEC is still considered by many as a new emerging eddy current NDT&E technique. Compared to other eddy current testing (ECT) techniques this view can .
