5th WSEAS Int. Cnfeence n Appled Electagnetcs, Weless and Optcal Cuncatns, Tenefe, Span, Decebe 14-16, 2007 127 Optzatn Fequency Desgn f Eddy Cuent Testng NAONG MUNGKUNG 1, KOMKIT CHOMSUWAN 1, NAONG PIMPU 2 AND TOSHIFUMI YUJI 3 1 Depatent f Electcal Technlgy Educatn Kng Mngkut s Unesty f Technlgy Thnbu,Bangkk 2 Suanaee Unesty f Technlgy, Naknatchasa THAILAND 3 Ota Natnal Cllege f Technlgy, Ota JAPAN Eal:nang_kutt@yah.c Abstact: The pupses f ths eseach wee t cnstuct the nndestucte etal testng ntuent by usng eddy cuent ethd and t fnd an ptal fequency f the etal testng ntuent. The testng ntuent cnsst f a sne wae scllat ccut whch can adjust the fequency between 20 90 khz, and a 50 hs sens ccut. Thee ae thee knds f testng ntuent. The fst was the nndestucte pefectn testng by usng eddy cuent ethd. The saple ns ae cnstucted wth dffeent pefectn n suface. The utput sgnals f testng f the sens ccut ae cpaed. The secnd was the nndestucte categzatn etal testng by usng eddy cuent ethd. Many knds f etals ae taken t testng. The last ne was the nndestucte testng f fndng the thckness f fls n n by usng eddy cuent ethd. In ths testng the thckness f fls aed between 100 700 cns. In all testng, dffeences f the sgnal testng wee cpaed t analyze the ptal fequency f the testng ntuent. The esults f eseach shwed that the nndestucte etal testng ntuent by usng eddy cuent ethd can be used t fnd a dffeent pefecte n, categze the etal and fnd thckness f fls. In addtn, the ange f an ptal fequency s 30 khz t 70 khz f testng ntuent. Keywds Nndestucte, eddy cuent, thckness f fls, ptal fequency 1. Intductn Nwadays Thaland has s any ndustal deelpents; theefe, thee ae a lt f nests, bth lcal and ntenatnal. In de t be able t cpete wth the cuntes, Thaland needs t cntl ts pductn standads and elablty [1]. Standads ae the key fact f Thaland ndusty. That s t say, t deelp ndusty eans t deelp technlgy f the st pat. At the ent, thee s technlgy called nndestucte etal testng whch s wdely used n the ndusty. Ths technlgy s used f 3 pupses, whch ae t ensue assue the qualty cntl, t test the qualty accdng t the standads, and t keep antenance. The wdely used nndestucte etal testng ethd n the ndusty s Eddy Cuent Methd Testng ET, f exaple, t test etal qualty suface f etal. Eddy cuent culd be ade by hgh fequency agnetc feld. The agnetc feld happens when hgh fequency AC cuent entes pay cl. In case thee s cntnuus space nsde the wk ateal, the eddy cuent wll be hghe. In case thee s n cntnuus space nsde the wk ateal, the eddy cuent wll be lwe. Ths dffeence culd be used t easue the cntnuty f the wk ateal by usng eddy cuent [2-4]. Ths eseach was t desgn and deelp nndestucte etal testng ntuent by usng eddy cuent ethd, whch cnssted f scllat ccut whch can adjust fequency and a 50 hs sens ccut, and t exane the pact f used fequency n testng as well. 2. Analyss and Desgn Desgn f etal testng ntuent was t be used n fndng pefectn f n, categze any knds f etal, and t fnd the thckness f fls n n suface by nndestucte testng. The eseaches appled the pncples f eddy cuent t desgn sne wae scllat whch culd adjust fequency between 20 90 khz, wth a 50 hs sens ccut. Detals elated t the analyss and the desgn culd be shwn n fs f blcks cntllng each pat f f nndestucte etal testng ntuent by eddy cuent ethd as fllws:
5th WSEAS Int. Cnfeence n Appled Electagnetcs, Weless and Optcal Cuncatns, Tenefe, Span, Decebe 14-16, 2007 128 Sens Apl fe Oscls cpe Pwe Apl fe Mete 470Ω Oscllat 1kΩ Fgue 1. Cpnents f the Nndestucte Metal Testng Syste by Eddy Cuent Methd 5kΩ 5kΩ 2.1 Desgn f Wae Oscllat Ccut[5] Sne wae scllat ccut culd be sply ade by ne IC n de t educe the cplexty f desgn and ateal. IC nube X2206 whch culd be fund at a easnable pce and easy t desgn was used. The ccut stuctue was as shwn n Fgue 2 and the fequency s 1 f = C 2.2 Desgn f Ccut f Electcal Vltage Aplfcatn Sgnal f scllat ccut ust be aplfed s that t culd be used n a pactcal way. Theefe, ccut f electcal ltage aplfcatn ust be desgned by usng p-ap nube CA3130. Ths ccut wuld wk faste and culd be used wth dffeent ange f fequency. Pncple n desgn and pactce was based n netng type sgnal aplfe ccut. Gan ate depends n and f and culd be calculated by aplfe ate A CL f ccut n Fgue 2 as shwn n the fllwng equatn: f ACL = (2) Theefe, utput culd be calculated by the equatn: f VO = xe (3) 2.3 Desgn f Ccut f Electcal Pwe Aplfe Sgnal f scllat ccut had t be aplfed by netng type aplfe ccut. The utput sgnal was hghe but that sgnal culd nt de 50 hs; theefe, ths sgnal had t be aplfed by tansst aplfe ccut. Tansst nube H1061 was electcal pwe aplfe s that t culd dstbute ltage t 50 hs sens ccut (1) Fgue 2 Wae Oscllat Ccut A β' L = = (4) n π A = V Z n = A (5) n L G= A A (6) = A V = V (7) 2.4 Desgn f Sens Ccut Inducte cl was an electcal lad. Electcal cuent whch uns thugh cl wuld nduct because agnetc lnes f fce tk place nsde nducte cl. Vltage dp f nducte cl f ccut culd be calculated by the fllwng equatn: V L n dl = L = L( ωi csωt) = ωli csωt (8) dt When sens ccut was used t test pefectn f etal by usng nndestucte eddy cuent ethd and sens ccut gt clse t etal. The nductance alue f the cl wuld change. Ths change was due t aus easns lke etal type, sze f pefectn, dstance and scllat fequency. Thus, nductance alue f sens changed dffeently. 3. Expeent Ths expeent was t cnstuct 3 knds f nndestucte etal testng by eddy cuent ethd as fllws[6-8]: 1. The fst was t d a nndestucte test f etal pefectn by usng eddy cuent ethd. The test was a sulatn by akng dffeent pefectn sze n etal and then sens ccut was used t test s
5th WSEAS Int. Cnfeence n Appled Electagnetcs, Weless and Optcal Cuncatns, Tenefe, Span, Decebe 14-16, 2007 129 by adjustng fequency between 20 90 khz dung the expeent. Fgue 3 A Nndestucte Test f Metal Ipefectn by Usng Eddy Cuent Methd 2. The secnd was t d a nndestucte categzatn f etal by usng eddy cuent ethd. The test was a sulatn by takng any knds f etal (n, cppe, bass, alunu and stanless steel) t the test n de t categze etal. The test was dne by sens ccut wth a 50 hs ccut and the fequency used was aund 45 khz dung the test. Fgue 5. A Nndestucte Test t Fnd the Thckness f Fls n In by Usng Eddy Cuent Methd 4. esults 4.1 esults f Nndestucte Test f Metal Ipefectn Nndestucte test f etal pefectn by usng eddy cuent ethd was the test t fnd ut the dffeences f pefectn n n. Saple n had been dlled wth dffeent wdth and depth n suface. The fequency used was between 20 90 khz and then the utput sgnals wee pltted n a gaph t cpae the dffeences f pefectn. 6.10 6.05 6.00 1 hle length 2 hle length 3 hle length 5.95 Fgue 4. A Nndestucte Test f Metal Categzatn by Usng Eddy Cuent Methd 3. The thd was t d a nndestucte test f fndng the thckness f fls n n by usng eddy cuent ethd. The thckness f fls n the test aed between 100 700 cns. The test wuld ncease 100 cns f fl thckness n each te and the fequency used was between 20 90 khz n de t fnd ut the ptal fequency. It was fund that the fequency between 30 50 khz shwed the st bus esults f sgnal change. Ths fequency was then was the ptal fequency. Vltage () 5.90 5.85 5.80 5.75 5.70 5.65 5.60 0.00 1.00 2.00 3.00 4.00 5.00 Hle daete () Fgue 6. In pefectn at 40 khz 4.2 esults f Nndestucte Test f Metal Categzatn Nndestucte test f etal categzatn by usng eddy cuent ethd was the test t fnd ut the
5th WSEAS Int. Cnfeence n Appled Electagnetcs, Weless and Optcal Cuncatns, Tenefe, Span, Decebe 14-16, 2007 130 dffeences n knd f etal (n, cppe, bass, alunu and stanless steel). The fequency used was aund 45 khz. The utput sgnals wee pltted n a gaph as shwn n Fgue 7. 4.3 esults f Test f Fl Thckness n Ins Nndestucte test f fl thckness n n by usng eddy cuent ethd was the test t fnd ut dffeences n fl thckness. Fls wth 7 dffeent knds f thckness wee used f the test wth dffeent fequency. The utput sgnals wee pltted n gaph t shw the elatnshp twads t fl thckness as Fgue 8-9. Fgue 7 Gaph f Electcal Attbute f Metal Fgue 8 Typcal Test at 40 khz Magnet01 Magnet0 Usua l Stalet Bas s Alunu Cppe Fgue 9 Typcal Test at 60 khz 5. Cnclusns Ths eseach was t ppse hw t desgn and cnstuct nndestucte etal testng ntuent by usng eddy cuent ethds. Thee wee 3 knds as fllws: 1. Nndestucte test f etal pefectn by usng eddy cuent ethd was a sulatn test by akng dffeent pefectn sze and then 50 hs sens ccut was used t test. It was fund that the fequency between 50 70 khz shwed the st bus dffeences and t was sutable f ths knd f test. 2. Nndestucte test f etal categzatn by usng eddy cuent ethd was a sulatn test by takng any knds f etal t the test and then 50 hs sens ccut was used t test. It was fund that n shwed the bus dffeences and t was sutable f ths knd f test. 3. Nndestucte test f fl thckness n n by usng eddy cuent ethd was dne by testng fls wth thckness f 100 700 cns. The test wuld ncease 100 cns f fl thckness n each te and the fequency used was between 20 90 khz n de t fnd ut the ptal fequency. It was fund that the fequency between 30 50 khz shwed the st bus dffeences and t was sutable f ths knd f test. F ths study, t culd be cncluded that the testng nstuent f eddy cuent ethd culd be used t d nndestucte etal tests elated wk n any ndusty. Due t the patent easn, the nfatn f ths nstuent des nt shw n e detal. efeences [1]. Fuj Sat, Pathat Panthubanyng, Pundtj Aayannt, Kkat Bunchukusl, Syt Ssatht, 1987, Nndestucte Test, 2 nd
5th WSEAS Int. Cnfeence n Appled Electagnetcs, Weless and Optcal Cuncatns, Tenefe, Span, Decebe 14-16, 2007 131 Ipessn, Technlgy Ptn Asscatn (Thaland-Japan), Bangkk, pp. 197-212 [2] T. Takag, M. Hasht, H. Fukut, M. Kukawa, and K. Mya et al., Benchak del f eddy cuent testng f stea geneat tube: expeent and nuecal analyss, Intenatnal Junal f Appled Electagnetcs n Mateals, l. 5, n. 2, pp. 149 162, 1993. [3] H. Fukut, H. Huang, T. Takag, and J. Tan, Identfcatn f cack depths f eddy cuent testng sgnal, IEEE Tansactns n Magnetcs, l. 34, n. 5, pp. 2893 2896, Sept. 1998. [4] A. Kaea, Slutn f asyetc cnduct wth a whle by FEM usng edge-eleent, COMPEL, l. 9, pp. 230 232, 1990. [5] Wte Asaaangsee, Chatchawal Tetwng, Knchulee Chasatht, 1988, Usage f Op-Ap and Lnea IC, 1 st Ipessn, Se-Educatn, Bangkk, pp. 197-201 [6] V.S.Cecc, G.Van Dunen,and F.L.Shap, 1986, Adanced Manual F: Eddy Cuent Test Methd, Canadan Geneal Standads Bad, Canada, pp 5-24 [7] Tshyuk Takag, 1998,Nuecal Ealuatn f Celatn between Cack Sze and Eddy Cuent Testng Sgnal by a Vey Fast Sulat,IEEE Tansactns n Magnetcs, Vl. 34, N. 5, Septebe 1998, pp 2581-2587 [8] Xa-Me Pe, 2002, A Fequency Spectu A n a l y s s M e t h d f E d d y C u e n t Nndestucte Testng, Pceedngs f the Fst Intenatnal Cnfeence n Machne Leanng and Cybenetcs, Bejng, 4-5 Nebe 2002, pp. 1194-1197