Bsi bs en 60404 4 1997 (2002)

BRITISH STANDARD BS EN 60404 4 1997 Incorporating Amendment No 1 Magnetic materials — Part 4 Methods of measurement of d c magnetic properties of magnetically soft materials The European Standard EN 6[.]

Magnetic materials —

T he E uro p e an St an d ard EN 6 0404 -4 :19 97, wi t h t he in c o rp or a tion o f

a m end me nt A1: 200 2, has t he s tat us o f a B r itis hS tand ard

I C S 29 03 0

T he s tar t an d fi ni sh of t e xt in tro d uce d or a lte r e d b y a m end m e n t is in d ic at ed in

th e te x t b y t ag s !" T ags ind ic ati ng c ha n ge s to IEC te xt c ar r y t h e num ber

of the I EC ame n d m en t F or e x am p le, tex t a lte r e d by I EC am e nd m ent 1 i s

in d ic at e d b y ! "

T he U K p ar ti c ip ati on i n i ts p r ep ar a tion w as en t r us t e d to T ec hn ic a l Co m mitt ee

ISE /N FE/5 , M ag net ic al loy s and s te el s, w hich ha s t h e re s po n si bili ty to :

— aid e n quir er s to u n der s tan d t he t ex t;

— p r es ent to the r e sp o n si ble inte r n at io na l/Eu r o p ea n c om m i tte e an y

e nquiri es o n th e in te r p r et ati on , o r p r opo s als for c h an ge , a nd k ee p the U K

T he Bri tis h St an d ard s which imp lem en t inte rnati on al o r Eu rop e an

p ublica tio ns r efe rred t o i n this d oc ume nt ma y be fo u nd in t he BSI Cat a l ogue

un d er t he s ec t io n ent itled “In ter n at io nal S tand ar d s Cor r es po n d en c e I nd ex ”, o r

by us in g the “S ea r ch” facili ty of the BSI Ele c t r oni c Cat a l ogu e or of B ritis h

St and ar d s O nl in e

T hi s p u bl ic at ion do es n o t p u r p or t to i nc l u de al l th e ne c es sar y pr ov is ion s of a

c ontr ac t U ser s ar e r es p ons ibl e for it s c or r ec t ap p l i c ation

Com pl ian c e w ith a B r itish St an dar d d oe s n ot of it se l fc o n fer im m u n ity

fr om le ga l ob li gati on s

Sum mar y o f p ages

This d ocu men t c omp r ises a fr on t c over , an insi de fr ont cov e r, pa ge s i an d ii,

theEN ti tle p ag e , pag es 2 to 25 and a b ack co v er

The BSI c opy r ig ht n ot ic e d is p lay ed i n thi s d oc u m en t ind ic at es wh en t he

d ocu me n t w as la st is sue d

Am e n dm e n ts is sue d sin ce pu b l ic atio n

20 02

S ee n at iona l fo r ew o r d

( inc lud es amen d ment A1:2 002 )

Th i s Eu ro pean S tand ard w as a p pr o v ed by CEN EL EC on 19 96- 12 -0 9

Am en dme nt A1 wa s ap pr o ve d by CENEL EC on 20 01- 12 -0 2 CENEL EC

me mbe r s ar e bo und t o c om pl y w it h t h e CEN/ CEN ELE C Int er nal Reg ula t io ns

wh ic h st ip u lat e t he c o n d iti on s fo r giv in g this Eu r o pe an S tand ar d t h e s ta tus of a

nat iona l s tand ard w it hou t any alt era tio n

U p -t o- d at e lis ts and b ibli og r ap hic a l r e fer enc es c onc e r ning s u c h na tio nal

st and ar d s may b e ob tai ned on a pp li c ati on t o th e Centr a l S ec r eta r iat or to a ny

CENEL EC me mbe r

Thi s Eur opea n S ta nd a r d ex i s ts i n thr ee offic ia l ver si ons ( Eng lis h, F r enc h,

Ger m a n) A v er si on in an y ot he r l an gu ag e m ad e by t r ans lati on und e r t he

resp o ns ib ilit y o fa C EN ELEC memb er i nto its own l an g u ag e a nd no ti fi ed t o t h e

Centr al Se cr et ar ia t has th e s ame st at us as t he offi c ial ve r si ons

CEN EL EC m em ber s ar e t he na tio n al ele c tr o t ec h n ic al c om m itt ee s o f Au st r ia,

Be lg iu m, D e nm ark, Fin la nd, Fra nce, Ge rman y , G re ece , Ice lan d , Ir e land , It aly ,

Lux e mbou rg, Ne t he r lands , No rw ay , Po rt ug al , S pain, S w ed e n , S w it z erla n d a nd

U nite d Kin gdo m

CENEL EC

E ur op ean Com mi tt ee for El ec t ro te c h nic al St a n da r d iza t ion

Co mit é Eur opé en d e No rm alis at ion Ele c tr o tec hn i que

Eur o pä isc he s Kom it ee für Ele kt r ot ec hni sc he N or m u ng

Cen t ral S ec r e tari at : ru e de St assar t 35 , B - 1 05 0 B ru sse ls

© 19 97 CEN ELEC — Al l rig ht s of e x p loitat io n in any for m and by any me ans res er ve d w orl dw id e for

The t ex t of the I n te r n at ion a l S tan d ar d

IEC4 04- 4:1 995 ,p rep a red by IEC TC6 8, M ag n e tic

al loy s and s te el s, w as s u bmit ted to the for m a l v ot e

an d w as ap p r o ve d by CEN EL EC a s EN6040 4- 4

on199 6- 12- 09 w ith o ut a ny mo d ificat io n

The follo w in g da te s w e r e fi xed :

An n e xe s de s ig n ated “no r m at ive ” ar e p ar t o f the

bo d y of t he s ta nd a r d

An ne xe s des ig n ate d “infor m ati ve ” ar e gi ven for

inform atio n o nly

In t his s tandar d , Anne x A a nd A nne x ZA are

Th e te x t o fthe am e n d m ent 1:2 000 to the

Int e rnation al S t an d ar d IEC60 404 -4 : 19 95,

p r ep are d by IEC T C68 , M ag net ic all oy s and st ee ls ,

w as s ubm it te d to th e Un i que Ac ce p ta nc e P r oce d u r e

an d w as ap p rov ed by CEN ELE C as ame nd m en t A1

to EN60 404 -4 :19 97 o n20 01- 12 -0 1 w it ho ut an y

m od i fi ca tio n

Th e fol lowi ng d at e s w e r e fix e d :

E n d or se m e n t n o tice

The te x t o fame nd men t 1:2 000 to th e In te rnat i onal

St and ard IEC6 040 4- 4:19 95 w a s a pp r o v ed by

CEN EL EC as an a mend me nt t o t he Eur op e an

ame nd m ent has to be

imp lem e nte d at na tion al

lev el by p ublica tion o f an

id e ntica l n at io nal s ta nda rd

Cont en ts

Pag e

3 D eter m in at ion o f th e m ag ne tic

c h ar a c te r ist ic s by the r i ng m ethod 4

3 6.4 D ete r m inat ion of n or m al

3 6.5 D ete r m inat ion of a c o m p lete

3 7 U nc e r tai nt y by the r in g m eth o d 9

4 D eter m in at ion o f th e m ag ne tic

c har a c te r ist i cs by the

4 4.4 De te rmin a tio n o f t he no rmal

for th e J- c om pensa te d c oil sy s tem 24

Ann ex Z A (no r m at iv e) N or m ati ve

re fe re nc es to int ern at io nal p u bl icat i ons

w ith th ei r c or re s pond in g E ur op ean

1 Scope and object

This p ar t o f I EC60 404 s p ec i fi es th e m e t hod s o f m ea s u r ing the d c m ag net ic p r op er tie s o f ! magnet ic all y

s oft m ate rial s" ir o n and s te el in a cl os e d m ag n et ic c ir c u it u si ng eit he r t h e r i ng o r th e p er m ea m et er

m e tho ds ! T h e r i ng m et hod is s ui tab le for us e wi th la minat e d o r so li d ri ng s p eci m en s as w el l as ring

s pec im e n s pro d u c ed by s in t er in g "

T wo m e tho d s a r e u s ed :

a ) th e r ing met hod , pa rt icul a rl y for m agnetic field s tr engths of up to10kA/ m ;

b) th e pe r me am e ter m eth od fo r m ag n etic field s tr en g t hs in the r ang e 1kA /m to 20 0k A/m

NO T E T he m e as ur e m en t o f c o e r c iv it y in a n op e n m ag n e t ic c ir c u i t is sp e ci fie d i n I E C60 4 04 -7

The follo w ing nor m at iv e do c u m ent s c ont ain p r ovi sio n s wh ic h, thr oug h r efer en c e in this te x t, c ons tit ute

p rov is io n s o f th is p art o f IEC604 04 At t h e t ime of p ubl icat ion , the ed it io ns i nd ica te d w ere v ali d Al l

no rm ativ e d ocume nts are s u bj ect to r evi sio n, an d p a rt ie s t o ag reem e nts bas ed o n t hi s p art o fIE C 60 404

ar e en c ou r ag ed to in v es ti gate the p os s ibil ity o f ap p ly in g the m os t r e c e n t ed itio n s of t h e n o r m at iv e

doc um ents ind i ca t e d b el ow M e m ber s of I EC a nd I S O m aint ain reg ist er s of c ur rentl y va lid Inte r nati ona l

St and ar d s

IEC 6 040 4- 7:19 82 , Ma gnet ic m at e ri a ls — Pa rt7:Met hod ofme as ur e m en t of t he c oe rc i vi ty ofm agne t ic

ma te r i a ls in a n ope n m agne t i c c ir c ui t

IEC 6 040 4- 8- 2: 19 85 , Ma gn et i c ma t e ri a ls — Pa r t8:Sp e c ific a t ions for i nd i v i dua l m at e r ia l s —

Se ct i on2:Sp e c i fic a t ion for c ol d-r ol l e d m agn e ti c a l l oye d s te e l s t ri p de l iv er e d in t he se m i- p r oc ess e d s t a te

IEC 6 040 4- 8- 3: 19 85 , Ma gn et i c ma t e ri a ls — Pa r t8:Sp e c ific a t ions for i nd i v i dua l m at e r ia l s —

Se ct i on3:Sp e c i fic a t ion for c ol d - rol l e d m a gne t i c n on - al l oye d s t e e l s t r ip de li v e r e d i n t he s e mi - pr oc e ss e d s t at e

IEC 6 040 4- 8- 4: 19 86 , Ma gn et i c ma t e ri a ls — Pa r t8:Sp e c ific a t ions for i nd i v i dua l m at e r ia l s —

Se ct i on4:Sp e c i fic a t io n for c o l d-r ol l e d no n- or i e nt ed ma gne t i c st e e l sh ee t a nd s t ri p

IEC 6 040 4- 8- 6: 19 86 , Ma gn et i c ma t e ri a ls — Pa r t8:Sp e c ific a t ions for i nd i v i dua l m at e r ia l s —

Se ct i on6:Softm a gn e ti c m e t a l l ic ma t e r ia l s Ame ndm en t 1 ( 199 2)

IEC 6 040 4- 8- 7: 19 88 , Ma gn et i c ma t e ri a ls — Pa r t8:Sp e c ific a t ions for i nd i v i dua l m at e r ia l s —

Se ct i on7:Sp e c i fic a t io n for gr a i n-o r i e nt e d ma gne t ic s te e l s he et a nd s t ri p Ame nd me n t 1 ( 199 1)

IEC 6 040 4- 8- 8: 19 91 , Ma gne t i c ma t e ri a ls — Pa r t8:Sp e c ific a t ions for i nd i v i dua l m at e r ia l s —

Se ct i on8:Sp e c i fic a t ion for t hin ma gne ti c s t e e l s t r i p for us e a t me d iu m fre q u e nc ie s

3 1 Ob je ct

Thi s c l au se d esc r ib es th e r in g m e th o d u se d to o bta i n the n o r m al m a gne ti zation c u r v e an d the h y ste r e si s

lo op

3 2 Ge n e ra l

Thi s m eth od is u se d p ar t ic u lar ly for m agne tic fie ld str e ng ths of u p to10kA/ m H ow e ver, i f c ar e i s ta ke n t o

av o id hea ting t he t es t s p ec i m en , th is m et h od m a y be u se d at h igh er m ag ne tic fi eld s tr e n g th s

3 3 E ffec t of t e mpe rat u re on the m e asu re me n ts

Care s hall be tak en to av oi d un d uly he ati n g t he te s t sp ec im e n The m e as ur em e n ts sha ll b e m a d e a t an

amb ient te m p er atu r e o f( 23±5)°C The te mp er a tu r e of t he t es t s p ec i m en s hall n ot e xc ee d50° C w hic h

s ha ll b e m onit or e d by m eans of a te mp er a tur e se n so r

F or m at er i als whi c h a r e p ar t icu lar ly te m p er atur e se n si tiv e, pro d u c t s tand ar d s m ay d e fin e lo w er or hig h er

te s t s p ec ime n t em p e r atu r es

3 4 Te st sp ecim en

T h e t es t sp e c ime n is a h o m og e neo us u nw e ld ed r in g of r ec t ang ular or c ir cul a r c r os s -s e c ti on T he

c r o ss - sec tion al a r ea of th e r i ng is dete r m ine d b y t he p r od u c t d im e ns ions , un ifor m i ty of m ag n et ic pr op e r tie s,

ins trume ntat io n sen si tiv it y an d sp ace re qu ire d for t he t es t wi ndi ng s U s ua lly t he cro ss - se c tio n al are a is

Ca r e s h all be ta ke n in the p r e pa r ati on o fth e tes t s pec im e n to avo id w o r k h ar d e n ing or h e at ing of t he

m a te r ial whic h m igh t affec t the magnetic c ha r ac ter i s tic s T h e t es t sp ec im en can be p r ep a r ed by t u rni n g

a nd fin is h ed by lig h t g r in d in g w it h s uffi c ient c oo l ant to p r e vent h eat ing t he m at er i al T h e edg es of t h e r in gs

s h all be d eburr e d

T o r ed uc e th e effect of th e r ad ial va riat i on of t he ma gne tic fi eld s tre n g th, t he follo w in g rel ation s hi p sh al l

a pp ly :

! T his re lat ions hip s h all a pp ly fo r mea su r em en t s on l am in ate d o r so lid ring t es t sp e cime n s Fo r sin t ere d

ma gne tica lly s o ft mat e ri als , w h e r e th e finis h ed di m ens io n s a r e usa lly s m all , t he follo w in g relat io ns h o p c an

b e us ed :

In t hi s c a se t he r e w ill b e a g r ea te r r ad ial v ariat i o n in th e ma gne tic fi eld s tr en g th "

T he di m en s io ns o f the t es t s p ec i m en s h all be d ete r m in ed b y mea sur ing t he outs id e an d in s id e d iame te r s of

t he r i ng t og e th e r w ith t h e h e ig h t o r d iame t er u s ing a s u ita ble mic r om ete r or ver nier g auge T he m ea n

c r o ss - se c tio nal ar e a s h all be c alc u la ted wi th an un c e r ta in ty of ±0 ,5% o r be tte r

T he m ean mag net ic pa th le ngt h o f t he t es t sp e cim e n s h all a lso be calcula te d w it h an u nc e r taint y o f±0 , 5%

or be tt er fro m th e r e lat io n ship :

3 5 Win di n g s

Be fore w i nd in g , a co n ne ct io n s hall be m a de to t he c or e i n or de r t o c hec k s u bs eq ue ntl y the i ns u lat ion o fth e

w ind ing s, a te mp er atur e s e n so r s hall b e at tache d t o the t es t s pe c im en and t he n the r in g shal l be o ver l a id

w it h a t hi n lay e r of i ns u lat in g mat er ia l

F ir s tly, a se c on da r y win di ng of ins ul at ed c op p er w i r e s hall b e w oun d ev e nl y r o und th e c or e Th e d im e ns i ons

of the se co nda r y wi nd i ng s h all be d et er mi ne d and t h e me an cro s s- se c ti onal are a, A

c, o fthe se c on dar y

w ind ing s ha ll b e ca lcu lat ed

A m ag ne t izin g w ind ing of w ire cap ab le of c ar r ying t he ma xi m um m agnet iz ing c ur r ent an d of a s uffic i ent

n u m be r o f tur ns to p r od u c e the m ax im u m r e qu ir ed m ag net ic fie ld s tr en gt h sh al l be e venly w ou nd i n one

o r mo r e l ay er s on th e c or e T h e m agn et iz ing wi nd ing c an c onsi s t of:

a) a la rge n um be r o f t urns of a sin g le c o nduc t or a p pl ied c l os e ly and u nifor mly r o und the who le r in g ; o r

b) a sma ller n um ber o f tur ns of a mu lt icore cab le a pp l ied c lo s ely a nd u nifor ml y r ound the w hol e r i ng; t he

en d s of t he c on d uc t or in the in d iv id u al co r es b ei n g i nte rc onn ec te d to g iv e t he e ffect of o n e m ultil ay e r

wi nd i ng ; or

c) a n ar r angement of r igid , or par t r ig id and p ar t flexi ble, c onduc t or s w hic h c an b e o p e ned to a dm i t t he

r ing ( c ar r y ing the se c onda r y w ind i ng and i ns ul ati on ) and th en c losed to fo r m a unifor mly wo und tor oi d

If nece ss ary , t h e w ou nd rin g is imme rse d in an oil bat h or subj e ct ed to an ai r bla st in o r de r t o co o l it

NO T E I f t h e a b o ve a r ran g e m e nt s a re u s e d w i t h a u ni fo rm ly d is t r i but e d s e co nd a ry win din g, an e rr or , w hi c h m a y b e pr e s e n t in an y

r ing te st , i s lia b le t o b e m a g nifie d a nd t o b ec o m e o f c o n s ide r a b le i m p o rt a n ce T h is e rr or a r is e s b e ca u s e, i n wi n di n g a rin g s p ecim en

t or oi dal ly , a n e ffe ct iv e ci r cu la r t u rn o f d iam e te r e qua l to t h e m ean d iam e t e r o f th e r i n g is pr od u c ed

T h e flu x be t w e e n t h e e ffec ti v e m ut u al ly in d uc t iv e ci r cu la r t ur n s o f t he m a g ne ti z ing w i nd i ng an d s ec o n da r y w i n di n g, as s ocia t e d w it h

flu x pa r a lle l t o t h e a x is o f t he rin g , is a d de d t o , or su b t r act e d fr o m t h e c i rc u m fe r en t ia l flu x W h e n a m u lt ico nd u c t o r ca bl e i s us e d fo r

t h e m a gn e t iz in g w in din g, t h e n u m be r o f t u rn s in t h e prim a ry o f t h e su p p l em en t a r y m u t ua l ind uc t a n ce is i n c r ea s ed i n p r op o rt i o n to

t h e n u m b e r o f co re s , an d t he er ro r fro m t h is so u rc e, p ar t i cu la r ly at h i gh fi el d-s t r e n g th s w h e r e t h e pe r m e a b il it y o f t h e t e st sp ec im e n

is r edu ce d, m ay am ou n t t o s ev er a l pe r c e n t T o e li m in at e t h is er ror a t u r n sh o u ld be w o u nd b a ck o n t h e s ec o n da r y w ind ing a lo n g t h e

me an c ir cu m fe re n c e o f t h e r i n g, o r , pr efer a bly , th e m agn e tiz in g c ab le s ho ul d be w o u n d i n pa i rs o f l ay er s, a lt e r n a t e l ay er s b ei n g w ou n d

c loc k w is e and an t i-c lo c k w is e ar ou n d th e r i n g

3 6 Me t h ods of me a su re m e n t by th e rin g m e th od

3 6 1 Ma gneti c fi eld stre ngth

T he ma gn etiz ing c urre n t s h all be me as ur e d w ith an u nc ert ain ty o f±0,5% or be tt er Th e m ag ne tic field

s tre ng t h sh al l be cal c ulate d fr om the fo ll ow ing rel at ions h ip :

3 6 2 Ma gn etic fl ux d en si t y

The s ec on d ar y w in d ing N

2( B co il) s h all be con ne cte d to a flu x in t eg r at or ( e le ctro n ic int eg r at or, ball ist ic

galv ano m ete r or flu x me te r) the c ali brat ion o f w h ich s ha ll b e e s t ab lis h ed in ac cord a nce w it h one o f the

pr oc ed ur es given i nAnn ex B wi th an u nc er tai n ty of ±1% or be tt er

T he chang e s o f th e mag ne tic flu x d e nsit y sh al l be c al cul ate d from the fo ll ow ing relat ions hip :

F or di r ec t r ead i ng of the %B, t he flu x in t eg r at or may be ad j ust ed s o th at K

B/ (N

2

A ) bec omes a po w e r of1 0

P r ov id e d th at th e se c o nda ry wi nd ing is w o und c l os el y on t he t es t sp e c imen, the air flux inc l ud e d in t h e

s econ d ar y wi n di n g ov er t he rang e o f mag ne tic fie ld s tre n gt h0 t o4 kA/ m w ill b e insi gnifica n t an d n o

c or r ec t ion need be ap pl ied At higher v alues of ma g n e tic fi eld s tr en g th , a n air flux c orr ec t ion sh al l be

a pp li ed in a c c or d anc e w ith eq ua tion( 8)

3 6 3 Co n n e ctio n ofapp a ra t u s

T he a pp ar a tu s i s connec ted as sh own in F ig ure 1

A so ur c e of di rec t cur r ent E ( st ab i li zed d c su p pl y w ith a rip pl e con t en t of le ss t han0, 1%, o r a ba tt e ry ) is

c o nnec te d t hr ou gh a c ur r en t -mea s u r ing d evic e A a nd a r eve r si ng sw i t c h S

cont in uo us ly co n tr ollab le ou t p ut is used , re si st or R

is the numb er of tu rns o f m ag ne t izin g w in d in g of t h e rin g ;

l is the mea n mag net ic p at h le ng t h, in me tre s;

I is the mag n et izin g current , in a m per es

=

fo r th e d et er m i na tio n of the c om p le te h y st eres is l o op T he sec ond ar y ci r cu i t co mp r ise s the sec on da r y

w in d in g N

2

( B c oil ) c onnec t ed t o th e fl ux i n tegr a tor

3 6 4 Dete rmi nat i o n ofn orma l m ag ne ti za t io n cu rve

T he t es t s pec ime n sh al l be car efu ll y d emag net ize d fr o m a mag n et ic fiel d s tre ng th of n o t le ss than5kA/m

b y t h e re p e ated r eve r sa ls of a gr a d ua lly re d uc i n g d em ag n et izin g fie ld T es t s p ec i men s w h ic h h av e be en

s u bj ect ed t o a hig her ma g ne ti c fiel d st reng t h s hall be d ema gn eti zed fr om a s u ita bly hig h fie ld be fo re te st

( for e xamp le , w h en m ac h in ed us ing a m a g neti c c hu c k)

N OT E I n or d e r t h a t t he m a gn et ic fie ld m a y c om pl e t e l y p e n et ra t e t h e t e s t s pe cim e n, t h e dw el l t im e aft e r e a ch rev e r s a l sh o u l d be

gr e a t e r t h an 2s fo r a c ro s s -s e ct io n 1 0m m×1 0m m , a nd 1 0s o r a c ro s s- s e ct io n 2 0m m×2 0m m

T he flux int eg rat or sh al l be c al ibr at ed b y on e o ft he met hod s d es c r ibe d inAn ne x B W ith S

2

c l os e d, th e

n o r m al m ag ne tiz ati on c u r v e sha ll t hen be d e ter m in e d by one o f th e fo ll ow in g m e th o ds

Me t hod A: c ont in uous r e c ord i ng m et hod

T o ut ili ze t h is m et h od , t h e o u tp u t fr o m t h e flu x in t eg r at or s h all be co nne c te d to t he Y ax is of an X -Y

r ec or d er , p lott er or c om p uter i nt er l a c e A low va lu e (e g.0, 17 o r17 ) c al ib r ated re si st or wi th t wo c ur r ent

a nd t w o v o lta ge t ermi na ls shal l be co n nect ed in se r ies w it h th e mag net izin g w ind in g T he p o ten tia l

t er m i na ls of thi s r es is tor s hal l be c onnec t ed t o th e X a xi s of t he r e c or der , p l ot te r or c om p uter inte r fa c e T he

s ys te m c an be c al ibr ate d o ver al l t o g iv e d ir ec t r ea di n gs o f m ag ne t ic flux de n si ty a n d m ag n e tic fie ld s tr en gt h

o n the r ec or d er , p lo tte r or c omput er i nter fa c e

T h e m ag ne ti zing c ur r ent sh al l be s te ad ily i nc r eas e d fr om ze r o to the v alue to p r od u c e the r equir e d

m axi m um m a gn eti c field st r en g t h T h e m a gne ti z ati on c u r v e is th en p r o d uc e d on t he X -Y r ec or d er , p lo tt e r

1

to

b ri ng th e mat e rial in to a s te ad y cy clic st a te S w it c h S

3

sh a ll be clo se d d urin g t h is op er at ion to ma intai n th e

flu x in teg r ato r at ze ro Wi t h sw it ch S

3

op en , t he fl ux i n tegr a tor r ea di ng c or r es p ond i ng to th e r ever s a l of th e

m agne tiz ing field s hall be r ec o r d e d a nd the c or r e s po nd ing m ag net ic flux d ens ity c a lcu lat ed

B y s u c c es si vely in c r eas ing the m agn etizi ng c ur r en t a nd r e p e atin g t his pr o c e dur e, c or r es p o nd in g v al ues of

m agne tic field s tr e ngt h and m ag ne t ic flux d e nsit y a re obt aine d fr om w h ic h t h e norm a l m a gn e ti zati on c u rv e

c an be pl ot te d

T h e m ag n etiz ing c u r r en t s h all ne ver be d e c r eas ed d u r in g t he m e asu r e m en ts, oth er wise th e t es t sp e c ime n

s h all be d ema gne tize d before r es umi ng me as ur emen ts

3 6 5 Dete rmi n at i o n ofa c o mpl et e hy steresis l oo p

T he t es t sp ec imen shal l be dema gnet iz ed i n ac cor da n c e w it h3 6 4 and the h y st er e si s l oo p sha ll b e

d ete r min ed b y on e o f the fo llow ing m eth o ds

Me t hod A: c ont in uous r e c ord in g m et hod

T h e ad di tio nal eq u ip m en t sp ec ified in m e th od A o f3 6 4 is req u ired Th e flux in te g r ato r s hall be ze roe d a n d

t hen a c ur r e nt o f v al u e s u ffic i en t to pr od uc e t he m a xi mu m m ag n et ic fiel d s tr e n gth r equ ir e d s hall be pa ss ed

t hr o u g h th e m ag net izing w ind in g N

1 Th is cur rent sha ll b e s lo w ly red uc ed to zer o, r ev er s ed, inc r eased to

it s m ax im u m ne ga tiv e valu e, r educ ed to z er o, r ev er s ed ag ain an d in c r ease d to it s m ax im u m p os it iv e v al u e

N OT E T h e cy c le sh ou ld be c om pl e t e d in a tim e be t w e e n3 0s t o6 0s, a lt ho u gh s om e m a t e r ia ls, e g.pu re ir o n , m a y r eq u ir e lo n ge r, in

o rde r t o all o w t i m e fo r t h e m a gn e t i za t io n o f t he t es t s pe cim e n t o fol lo w t h e a pp lie d m a gn e t ic fi e l d a n d yet av oi d s i gn ific an t dr ift o f t h e

flu x i n t e g r at o r z e r o w i t h t im e

Me th o d B: p o int -b y- p oi nt m e thod

Th e te s t sp ec im en s hall b e d em a gn eti zed an d a c ur r e nt s u ffic ie n t t o p r od u c e t he m ax im u m m ag n etic field

s tre ngt h req u ired s hall b e p as s ed thro ug h t h e ma gne ti zin g wi nd in g N

1 Th e tip p oi n ts of th e h ys te r esis lo op

s h all be d et ermine d by meas ur in g the c orre sp o nd ing va lu es o f mag n et ic field st r eng t h and mag net ic flux

The va lu e of the m ag n e tic fi el d st r eng th at eac h p o in t is c alcu late d fr om th e c or r e sp o nd in g m ea su r e d v alue

of cur r en t flow ing [ se eeq ua tio n( 3) ]

T he v al ue o fth e m ag n et ic flu x d en s it y a t eac h p o in t i s c a lcu lat ed fr o m the fol low in g r e lat io n sh ip :

P ort ion Q S o ft h e hy s te r es is lo op i s d e termin e d, w i th s w itch S

2

o p en, by clo sing s w itc h S

1 C ha nge s in

m ag ne tic field s tr en gt h an d m ag n e tic flu x d ens it y a r e m ea sur ed st ar ti ng w it h sw it c h S

1

in t he o p en

p os it ion an d c lo sing it to p o sit io n2

T he v alue of th e m a gne tic fie ld st r en g th at e ac h p o i nt is c al c u lat ed fr o m the m ea su r e d v alue of the c u r r en t

flo win g w h en S

1

is c lo se d in p osit ion2 [ se eequati on( 3) ]

T he v al ue o f th e m ag n et ic flu x d en s it y a t eac h p o in t i s c a lcu lat ed fr o m the fol low in g r e lat io n sh ip :

T o o bt ain th e c om pl et e hy s te r es is lo o p, th e s wi tc hi ng s eq u enc e s ha ll be in a c c or d an c e w it h the ar r a ng e m e nt

giv en i n Ta ble 1 t o main ta in the te s t s p ecim en in a s te ad y cycl ic st at e

T ab le 1 — Swi tchi n g se q u e n ce to m a in t ai n th ete st s pe cime n in

It is des irab le to mak e mea su r em e nt s on th e comp le t e hy s ter es is lo op , t o e limina te d r ift e rro rs in the flu x

int eg r at or Ho w ev er, s in ce p o rt ion S TU P o f th e l oo p is s y mmet r ical w ith p ort io n PQ RS , m eas ur e ment s may

is th e mag net ic flux d ens ity a t ti p of h y st eres is l oop , in t esla s;

%B is the cha nge in mag ne t ic flu x den s ity meas u r ed w h e n sw it ch S

is th e mag n et ic flux d ens ity a t the p oint Q , i n te s l as;

%B is the cha nge in mag ne t ic flu x den s ity meas u r ed w h e n sw it ch S

( Fi gu r e 2) ;

— r es is tor R

2: v alue s of m a gne tic fi eld s tre n g th + H½ or ÐH½ t h at i s po int s P ½ a n d T½ or p oints Q ½

and S ½ o n t he lo op (F ig u r e 2)

3 6 6 Dete rmi nat i o n ofrem an e n t flu x d e nsit y

F or a g iv en h y s te r es is loop , t he r e mane nt flux d e ns it y of t he m a te r ial is the va lu e of t he m a gne tic fl ux

d en sit y, i n t es las , w h en the mag n et ic fiel d s tren gt h is ze ro It sh al l be d ete rmin e d fro m t he p o sit io n o f po int

Q o n the h y st er e si s l oo p or the sy m m e tr ic a l p oi n t T

3 6 7 Dete rmi n ati o n ofco erci ve fie l d stren gt h

F or a g iv en h y s ter es is lo op , t he c o e r c iv e fie ld s tr e ng th of t he m ate r ia l is the v alue o ft h e m ag n et ic field

s tre ngt h, in amp ere s p er met r e, w hen t h e mag n et ic flux d ens it y is zero It s hall be d et ermi n ed fr o m p o int

R on t he h y st ere s is lo op or the s ym m e tr ic al p o in t U

3 7 Unc er tain ty b y th e ri n g me t h od

T he t ot al un c er ta inty in t he m eas ur e m en t of t h e m a g ne ti c fl ux d e nsi ty o r the m ag net ic field s tre ng t h

n o rmall y e x p ect ed is le s s t han or eq u al t o, ±2% w h e n usin g meas u r ing inst rumen t s w ho se e st imat ed

u nc e r tai nt y is le ss than , or e qu a l to ,± 1% for m ea su r em ent s b y the point by p oi n t me th od W he r e a

c om p le te m ag n et izat io n c u r ve o r h ys ter esi s lo op is d et er m in ed by t he c o ntinu ou s r ec or din g m et hod , t h e

o vera ll un c er t ai nt y m a y b e i n c r ea sed by the unc er ta in ty an d r e so luti on o f th e r ec or d er s y st em or c om pu t er

T he p r in ci pl e o f the ins tr umen t is il lust rated inF i g ure 3 andF ig ure 4 Th e t es t s p eci men i s c la mp ed

bet we e n tw o m as siv e st e el yo kes w hi c h pr o v id e a flu x c lo su r e p at h for the t es t s p ec i m en T h e yoke s ar e

fo r med fr om ei th er :

a) tw o st rip -w o und C- c ore s o fg r ain- o r ient ed s te e l as s pe c ifie d in IEC 6 040 4- 8- 7, o r

b) tw o st rip -w o und C- c ore s o fnick el iron a s sp e c ifi ed i n IEC 60 404- 8 -6 , o r

c) t w o s ta c ks of l aminat io n s cut fr o m e lec tr ica l s t e el as sp e cified in IEC 60 404 -8 -2 , IEC 6 040 4- 8- 3,

IE C 604 04- 8- 4, IEC 60 404 -8 -7 or IEC 60 404 -8 -8 , o r

d) t wo y o kes ma chin ed fro m so li d low ca rbo n st ee l o r s oft iron

F or t es ts o n round o r squa re b ars, p ole p ie c es s ha l l b e fab r icat ed fr om tw o p a irs of low carbo n st ee l or s oft

ir on b loc ks , e ac h p ai r being m a c h in ed to ac c o m m o d at e t he te st s p ec im en t o p r ov id e as c los e a fit as p o s si ble

( se eFi gu r e 3c an dFig u r e 3d ) The p ol e p ie c e s s h ou ld h a ve a p e r m e abil ity s u ffic ie n tl y h i gh t o p r od uce a low

re luc ta nc e p at h for t h e m agnet ic flu x pa ss in g b etw e en t he t e st sp ec im en and yo k es

T w o t yp e s of p e rm ea met er a r e sh o wn inFi gur e 3 a ndFi g ur e 4 hav in g t he follo w in g pr o p e r tie s:

T he r equi rem en ts of3 3 s hall als o ap p ly to the p er me ame te r me tho d s

Ty pe A: r an g e of m a gne tic fi eld s tr en g th:

mag ne tizi ng c o il:

m inim um l eng th of te s t sp eci men :

Typ e B: r an g e of m a gne tic fi eld s tr en g th:

mag ne tizi ng c o il:

m inim um l eng th of te s t sp eci men :

4 3 Te st sp e ci me n

U n le ss oth er w ise sp ec ifie d in the p r odu c t st and ar d s , the test s pec im en sha ll ha ve a m in im u m

le n gt hof2 50mm for t h e t y pe A p e r me am e ter , or100mm for the ty p e B pe rm eamete r, a minim um

a ) a r ound , squa r e, r ec t a ngu l ar or hexag onal b ar of uni for m c r oss - sec ti on

W h e r e i t is n e c es s ar y to m ac hine t he t es t sp e c imen to m inim iz e t h e air g ap b et we e n the s am p le and the

p o le p iec e s , th e s ur fa c e of the tes t s p ec ime n in c o n tac t w it h th e p ole p ie c e s s hall be tu r n e d or g r o u n d

us ing suffic ie n t c oo lant to p r ev e nt h e atin g t h e ma t e r ial; or

b ) fo r m at er i al c ut from s h ee t or c oil , one s tr ip o f w id th30mm s h all be cut p ar a lle l to t he d ire ct i on of

ro lli n g a n d on e st rip cut at ri gh t ang le s t o t he di rect ion of ro lling , a nd mea su red sep arat ely

T he c r o ss - se c tio n al ar ea o f t h e t es t s p ec i m en s hall be d et er m ine d from a n um be r of m e as u rem e nts of e ac h

n e ce s sa r y d im en sio n , equally s pa c ed ov e r the t es t l e ngt h The t r ans ve r se d im e ns io ns s h all be m ea su r e d b y

m eans of a m ic r o m et er at ap p r oxi m ate ly e v er y1 0m m al o n g the t e st le n gt h T he m e an c r o s s- s ec t ion al a r ea

s ha ll b e c om p u ted as the m e an o f the ar eas de te r min e d fr om t hes e m ea sur e m ent s wi th an un c er tai nty

o f ±0 ,5% T he d iffer e n c e be tw ee n t he g r e ate s t and s m all e s t o f the c r o ss -s e c tion al ar ea s sh al l n ot

exc ee d0,5% of the m ean ar ea

4 4 Me t h o ds of m e asu re m e n t by th e per me am e te r me th o d

4 4 1 Mea su re men t o f m a gn eti c fi eld strength

The m ag net ic fi eld st r en g th s ha ll be m eas u r e d w ith an u n c er t ainty of ±1% o r b et te r by one of the follo w in g

m eth ods :

Type A p e r me a me t e r s:

a) a s earc h - c oil o fle ngt h betw e en1 0m m an d50m m (s eeF ig u r e 5 c ) c on n ec te d to a m a gn eti c fl u x

i nt eg r a to r wh i c h sh al l be c al ibra te d in ac c o r d anc e w i th o n e o f the m e tho ds g iv en i nAn n ex B

T he s e ar c h- c oil usua l ly c omp r is e s t wo c oils c onn ec t e d i n s er i es ad d iti on a nd m ou nte d on e c oil on ea ch of

t wo o p p os ite s id es of the te st s pe c im en o r tw o c oil s c oaxia l w it h th e te st sp e c ime n w oun d in s e r ies

opp os iti on Th e c o ils s hall b e w oun d on n on -m a gne ti c , no n- c ond uc tin g for m e r s T he effe c ti ve ar ea- tu r ns

p ro duc t of the sea r c h- c oi l s ha ll b e d eter m ined with a n un c er ta inty of± 0, 5% b y o n e of t h e m e tho d s

i nAnnex A

NO T E T he n um b er o f t u rn s on t h e s e ar c h- coi ls d epe n d s u po n t h e s e n s it iv i ty o f t h e fl u x in t e g rat o r u s e d, an d als o u p o n th e ran g e

of m ag n e t ic fi e l d s t r en g th t o b e m e as u re d

b ) a H all e ffe ct d e vi c e o r o th e r p ass iv e me an s of d irec t ly se nsing a mag n e tic fie ld h a vi ng an u nc ert ai n t y

of±0,5% or b et te r Th ese d e vi c es c a n be c alib r ate d e it her in a s ui tab le s ole no id o f kno w n field t o c u r r ent

c on st an t or i n a un ifor m m ag net ic fie ld u si ng a n ap p r op r ia te nu c lea r magn et ic r eson an c e p r ob e

Type B p e rm e a me te r s :

c ) U s in g on e of th e m et hod s d es c r ibe d for t y pe A p e r m eam ete r s, p r ov id ed t h e v ar i ation of th e m ag n etic

fie ld s tr e n gt h in the r ad i al d ire ctio n can be de mo n st rate d t o be ins ig n ificant , o r

d ) a R og o ws ki -C ha tt oc k po t enti om ete r ( a C -s h ap e H-p ot ent iom et er c oil, se eFi gur e 5e) c onn ected to a

ma gne ti c fl u x i nte gra to r

T h e H- po t enti omete r c oil s hall com pri se a c onti nuo u sl y wo und c oi l whos e a xis lies on a se mic ir c l e

of40m m m axim um d ia met er or a com bi na ti on of di sc ret e s er ie s c onnec ted c oi ls wit h their a xes a r r an ged

s imil ar ly but n ot so a s t o i n tr o duc e s ig n ific an t d i sc o ntin uit ie s i n the in teg r atio n o f the m ag n et ic

p o te ntia l T he en d face s o fth e coil s y ste m s h all l ie w ithi n0,5mm of t h e s u r fac e of t he t es t s p eci m en

T h e e ffec t ive ar e a- t ur n s p r od u c t of the H- c oi ls s ha ll be d e te rmin e d wi th an u nc ert aint y of±0,5% by o ne

of the m e tho ds g iv en i nAn nex A

U si n g on e of t he c oil ar r an g em ents d e sc r ib ed i n a) or d) a bove , t h e c h ang es of the m ag n etic fie ld s tr e ng th

s ha ll b e ca lcu lat ed fro m th e re lat io ns hip :

F or di r ec t r ead ing of t he va l ues, th e fl ux in t eg r at or m ay b e ad j u ste d s o tha t K

H/[ 4

o(NA ) ] bec om es a p ow er

o f10

4 4 2 Me asu re me n t ofma gne t ic fl u x d en si t y

T h e m ag n etic flu x d e nsi ty shal l be m e as ur ed w ith an u nc er taint y o f±1% o r bet te r by one o f the fo llo w ing

m etho d s:

a) a fl ux- s ens in g co il ( B- co il, se eFi gu r e 5 a) , o f l e ngt h bet we e n10mm an d50mm, sh al l b e con ne cte d to

a flux inte g r ato r T h e ca lib rati on o fthe flux inte gr a to r s ha ll b e es tab lis h ed b y t h e met ho d g iv en

inAnn ex B

De p en d ing on th e le v el of t he m a gne tic fi eld s tr e n g th and t h e r e lat iv e c r os s- s ec t io na l a reas o f the te st

sp ec imen a nd flux - se n si n g co il , it m ay be n ece ss ary to ma k e a c or r ect i on t o the m ag net i c fl ux de nsi ty for

th e air flu x en c los ed by the flux- s ens in g c oil

Th e corre cte d v alue o fthe mag n et ic flu x d en s ity is g iv en b y the foll ow ing r elat ions h ip :

Alte r n at ive ly , a c o m pe nsa tin g c o il of e ffec tiv e ar e a e qu iv al en t to th at o fth e air s e c tion be tw e en t h e

wi nd i ng a nd t h e te st sp e c im en m ay be c on ne c te d in s er ies o p po s ition w it h the fl u x- s en s in g c oi l

Th e chang es in ma gne tic fl ux d e nsi ty sha ll be ca lcu lat ed fr o m th e relati ons hip :

b) by me asu r i ng t he m ag ne ti c p ol arizat io n w ith a n u nc ert a inty o f± 1% o r be t te r an d calcul atin g t he

mag net ic flux de ns ity fr om this v alu e an d the mag n e tic field s tren gth fr om th e rel atio ns hi p:

is th e c r o ss -s ec tio nal a r ea of t h e flu x- sen si n g c o i l , in s qu ar e m e tr e s;

A is th e c r o ss -s e c tion al a r ea of t es t sp e c im en, in s q u ar e m etr es

c– A

=

T h e m ag net ic p ol ar iza tion , J, s h all be mea sure d by me ans of c o mpen s ate d pol ariz a tio n c o ils (J -coil s,

s eeAnne x C) c onn ec ted to a flux int egr at or , c ali br a t ed by on e of t h e m eth od s give n inAnn ex B

Ac or r ec tio n for ai r flux is n ot n ec essa r y

T h e c ha nge s of t he m a gne ti c p ola r izat io n shal l be c al c u lat ed fr om the r el ati ons hip :

F or di r ec t r ea d in g of t he v al ue s , th e flu x in teg r at o r c an b e ad jus ted so t ha t K

J/( N

2A) b ec om es a po w e r

o f10

4 4 3 Co n n e ctio n ofapp a ra t u s

T he a pp ar a tu s i s c onnec ted as sh own i nF igur e 6

A so ur ce of di rec t c ur rent , E , ( st ab il ized d c s up pl y with a r ip p le c o nte nt of l es s than 0,1% o r a ba tte r y ) is

co nnec te d thr ou gh r ev er sing sw i t c h S

1

to t h e mag net izing wi ndi ng N

1 If a bi pola r c urr ent so ur ce is us ed,

r esis tor R

1

is not r eq u ir ed This is the ar r a nge m en t for th e m ea su r e m ent o f t h e no r m al m ag n et izat ion

cu r v e a n d hy s ter es is lo op s by t he c on tinuo us r ec o r di n g m et hod F or th e po in t -b y- p o in t m e tho d , s wi tc h S

2

and r es is to r R

2

ar e r eq ui r ed to d e te r m ine t he h ys te r e sis l oo p T he s econ da ry c ir c ui t c omp r is es a s e ar c h-c oil

w oun d ar o un d the tes t s pe c im en an d c o nn ec t ed t o a flu x inte g r ato r

4 4 4 Det ermi nat i on o ft h e n orma l m agn et i za ti o n curve

T he t es t s p eci men s h all be dema gneti zed i n ac c ord a n c e wi t h3 6 4

T he m a gn etic fl ux i nt egr a to r fo r t h e m e as ur em e n t of t he m a gn etic fi eld s tr e n g th and t h e m a gne tic fl u x

d ens it y or p olar iza tio n s h all be calib rate d in a c co r da nc e w ithA nnex B T h e no r mal m agnet izat ion c ur ve

s ha ll t h en b e d e te r m in e d by o ne o f th e fol low ing m e tho d s

Me t hod A : c onti nu ous r e c or di ng m e t hod

T o ut ilize t hi s met hod , t he o ut p ut fro m th e mag n eti c flux i nt eg r at o r conn ec te d to t he mag n e tic fie ld

s tr eng t h m e as uri n g co ils s ys te m sh al l b e c o nnec te d t o th e X in p ut of an X - Y r eco r d e r , p lott er o r c o m p u te r

int er fac e an d t he ou tp ut fr o m the m ag ne tic flux int eg r at or m easu r ing th e m ag n etic flu x d e n sit y or

p ol ar iz a tio n s hall be c o nne c te d t o th e Y inp u t o ft he X -Y r ec o r d er , p l otte r or c o mp u te r i nt er fac e T he sy s tem

s ha ll b e ca lib r ate d over all to give d i r ect rea di n gs of m ag n et ic field st r eng th a n d m ag net ic flux d en s i ty

T he m a gn eti zing c ur r en t shal l the n be inc r e as ed fr o m z er o t o the va lue r eq uir ed t o pr od u c e th e m ax im um

m ag n etic fie ld s tr en gt h T he m a gne ti z ati on c u r v e wi ll t h en b e p r od uc ed on the X- Y r e c or d e r , p lo tte r or

is t he numb er of tur ns o n th e po la rizat io n se nsing co il;

A is t h e c ros s- s ec t iona l ar e a o fth e t es t s p ec i m en , i n sq ua r e met r es