Iec 60454 2 2007

INTERNATIONAL STANDARD IEC 60454 2 Third ed i tion 2007 06 Pressure sensitive adhesive tapes for electrical purposes – Part 2 Methods of test Reference number I EC 60454 2 2007(E) THIS PUBLICATION IS[.]

I N TE RN ATI O N AL S TAN D ARD I EC 60 454-2 T h i rd e d i ti o n 200 7-06 P re s s u re - s e n s i ti ve ad h e s i ve ta pe s for e l e ctri cal p u rpos e s – P art : M eth od s of tes t Re fe re n ce n u m b e r I E C 604 54 -2 : 007(E ) T H I S P U B L I C AT I O N I S C O P YRI G H T P RO T E C T E D C o p yri g h t © 0 I E C , G e n e v a , S wi tz e rl a n d Al l or ri g h t s by re s e rv e d an y m eans, e i th e r IEC If h a ve yo u pl ease IEC 3, or an y C e n t l ru e I E C's co n ta ct de U n l ess o t h e rwi s e e l e ct ro n i c m em be r q u es ti on s th e or N ati o n a l abou t a d d re s s s p e c i fi e d , m e c h a n i ca l , IEC b el ow or no C o m m i tte e c o p y ri g h t yo u r p a rt i n cl u d i n g l o ca l in or th e th i s c o u n t ry h a ve IEC of pu b l i cati on p h o to c o p yi n g an of th e e n q u i ry m em ber an d be re p ro d u c e d wi t h o u t or u ti l i z e d p e rm i s s i o n in an y fo rm wri t i n g in fro m re q u e s t e r abou t N a ti o n a l m ay m i c ro fi l m , o b ta i n i n g C o m m i tte e a d d i ti o n a l fo r fu rt h e r ri g h ts to th i s p u b l i ca ti on , i n fo rm a t i o n O ffi c e V a re m b é CH -1 1 G e n e va 20 S wi t z e rl a n d Em ail : W eb : i n m a i l @ i e c c h www i e c ch Ab o u t th e I E C Th e I n t e rn a t i o n a l I n t e rn a t i o n a l E l e c t ro te c h n i c a l S t a n d a rd s fo r al l C om m i s s i o n e l e c t ri c a l , (I E C ) e l e c t ro n i c and is th e re l a te d l ead i n g g l oba l o rg a n i z a t i o n th a t p re p a re s an d pu bl i sh es tech n o l o g i es Ab o u t I E C p u b l i c a ti o n s Th e tech n i cal l ates t  C a ta l o g u e Th e It  e d i ti o n , IEC al so IEC S ta y J ust on -l i n e  If to C e n t re Em ail : of I E C on al so wi s h F AQ al l by or g i ve an on is ke p t am e n d m en t u n d er might c o n s ta n t h a ve been re v i e w by th e I EC Pl eas e m a ke s u re th a t yo u h a ve th e pu bl i sh ed ww w i e c c h /s e a rc h p u b en abl es yo u p ro j e c ts , to s e a rc h wi t h d wn by an d a v a ri e t y re p l a c e d of c ri t e ri a ( re fe re n c e n u m b e r, t e xt , tech n i cal c o m m i t te e , … ) p u b l i c a ti o n s ww w i e c c h /o n l i n e _n e ws / j u s t p u b n ew IEC pu b l i cati on s J ust Publ ish ed d eta i l s t wi c e a m o n th al l n ew p u b l i ca ti o n s re l e a s e d Ava i l a b l e em l S e rv i c e to p u b l i ca ti o n s or p u b l i c a ti o n s : P u b l i s h ed : an d IEC C atal o g u e i n fo rm a t i o n d a te C u s to m e r yo u of c o rri g e n d a on-l i n e g i ve s up co n te n t a C e n t re : us c o n t a ct cs c @ i e c c h Te l : +41 22 91 02 1 F a x: +41 22 91 03 00 yo u r u s: w ww i e c c h / we b s t o re /c u s t s e rv fe e d b a c k on th i s p u b l i c a ti o n or n eed fu rt h e r as s i s ta n ce, pl eas e vi s i t th e C u s tom e r S e rv i ce I EC I N TE RN ATI O N AL S TAN D ARD 60 454-2 T h i rd e d i ti o n 200 7-06 P re s s u re - s e n s i ti ve ad h e s i ve ta pe s for e l e ctri cal p u rpos e s – P art : M eth od s of tes t C o m m i s s i o n E l e ctro te ch n i q u e I n te rn a ti o n a l e P RI C E C O D E I n te rn a ti o n a l E l e c tro te c h n i ca l C o m m i s s i o n М еждународная Электротехни ческая Комисси я For price , X se e c urre n t ca talogue – – 60454-2 © I E C: 00 7(E) C O N TE N TS F O RE W O RD S cop e N o rm a ti ve re fe re n ce s C o n d i ti o n i n g a n d s p e c i m e n p re p a ti o n D e te rm i n a ti o n o f th i ckn e s s T e s t a p p a tu s Test s peci m en s P ro ce d u re 4 Re s u l ts D e te rm i n a ti o n o f wi d th M e th o d A M e th o d B M e th o d C D e te rm i n a ti o n o f ro l l l e n g th 10 11 P ri n ci p l e M e th o d A – M e a s u re m e n t o f tu rn s m e th o d M e th o d B – L e n g th s e n s o r m e th o d 1 C o rro s i o n - re l a te d p ro p e rti e s 1 G e n e l 1 P re p a ti o n o f wa te r e x tra ct fo r p H a n d co n d u c ti vi ty d e te rm i n a ti o n s 1 D e te rm i n a ti o n o f p H va l u e o f wa te r e xtra ct D e te rm i n a ti o n o f c o n d u cti vi t y o f wa te r e xtra c t D e te c ti o n o f c o rro s i ve s u l fu r I n s u l a ti o n re s i s ta n c e m e th o d 7 Vi s u a l m e th o d W i re te n s i l e s tre n g th m e th o d T e n s i l e s tre n g th a n d e l o n g a ti o n a t b re a k Ap p a tu s Test s peci m en s P ro ce d u re Re s u l ts L o w- te m p e tu re p ro p e rti e s P ri n ci p l e Test s peci m en P ro ce d u re Fl exi b i l i ty E l e c tri c s tre n g th Re s u l ts Re s i s ta n c e to p e n e tra ti o n a t e l e va te d te m p e tu re s 1 Ap p a tu s Test s peci m en s P ro ce d u re Re s u l ts Ad h e s i o n 60454-2 12 13 14 15 17 – – 1 P ri n ci p l e 1 M a te ri a l s 1 Ap p a tu s 1 T e s t s a m p l e s a n d te s t p i e ce s 1 P ro ce d u re 1 E x p re s s i o n o f re s u l ts Ad h e s i o n to b a cki n g a t l o w te m p e tu re s 1 Test s peci m en s 1 2 P ro ce d u re 1 Re s u l ts S h e a r a d h e s i o n to b a cki n g a fte r l i q u i d i m m e rs i o n 1 Ap p a tu s 1 Test s peci m en s 1 3 P ro ce d u re 2 Re s u l ts 2 C u ri n g p ro p e rti e s o f th e rm o s e tti n g a d h e s i ve ta p e s 2 B o n d s e p a ti o n d u ri n g th e rm a l tre a tm e n t ( a d h e s i ve to b a cki n g ) 2 B o n d s e p a ti o n a fte r th e rm a l tre a tm e n t ( a d h e s i o n to b a cki n g ) 2 F l a g g i n g te s ts 16 © I EC: 007(E) P ri n ci p l e Ap p a tu s Test s peci m en s P re p a ti o n o f s p e c i m e n s fo r te s t 5 T e s t c o n d i ti o n s Re s u l ts W a te r va p o r p e rm e a b i l i t y Ap p a tu s Test s peci m en s P ro ce d u re Re s u l ts E l e c tri c s tre n g th G e n e l Test s peci m en s P ro ce d u re Re s u l ts 18 E l e c tri c s tre n g th a fte r h u m i d co n d i ti o n i n g 19 Re s i s ta n c e to fl a m e p ro p a g a ti o n 20 P ri n ci p l e Ap p a tu s Test s peci m en P ro ce d u re Re s u l ts F l a m e te s t 20 P ri n ci p l e 20 Ap p a tu s 20 P re p a ti o n o f te s t s p e c i m e n 20 P ro ce d u re 20 Re s u l ts – – 21 60454-2 © I E C: 00 7(E) T h e rm a l e n d u n ce 21 D e te rm i n a ti o n o f th e rm a l e n d u n c e ( b a s e d o n I E C 6 - a n d I E C 6 - ) 21 Vo l ta g e b re a kd o wn 21 Loss of m ass 31 An n e x A ( n o rm a ti ve ) R o l l e rs to b e u s e d i n va ri o u s te s ts B i b l i o g p h y F i g u re – M e a s u ri n g d e vi c e fo r d e te rm i n a ti o n o f ro l l l e n g th o f ta p e ( m e a s u re m e n t o f tu rn s m e th o d ) F i g u re – M e a s u ri n g d e vi c e fo r d e te rm i n a ti o n o f ro l l l e n g th o f ta p e ( l e n g th s e n s o r m e th o d ) F i g u re – S e q u e n c e o f b e n d s 3 F i g u re – D i e l e ctri c s tre n g th te s t i n wa te r 3 F i g u re – S ke tc h o f p e n e tra ti o n te s te r F i g u re – S te e l te s t p l a te F i g u re – Arra n g e m e n t fo r s tri p p i n g th e ta p e fro m th e p l a te F i g u re – F l a g g i n g te s t – P re p a ti o n o f te s t s p e ci m e n F i g u re a – D u g h t p ro te cti o n d e vi c e F i g u re b – U s e o f B u n s e n b u rn e r a n d s l i d i n g p l a te wi th d u g h t p ro te c ti o n d e vi c e F i g u re – F l a m e te s t e n cl o s u re s F i g u re – E s s e n ti a l d i m e n s i o n s fo r fl a m e te s t ( p ro p o rti o n s e xa g g e te d fo r c l a ri t y o f d e ta i l s ) F i g u re 1 – D i m e n s i o n s o f we d g e T a b l e – C o n d i ti o n i n g fo r l o w te m p e tu re p ro p e rti e s 60454-2 © I EC: 007(E) – – I N TE RN ATI O N AL E L E C TRO TE C H N I C AL C O M M I S S I O N P RE S S U RE -S E N S I TI VE AD H E S I VE T AP E S F O R E LE C TRI C AL P U RP O S E S – P a rt : M e th o d s o f te s t F O RE W O RD 1) Th e I n t e rn a ti o n a l E l e c t ro t e c h n i c a l C o m m i s s i o n ( I E C ) i s a wo rl d wi d e o rg a n i z a t i o n fo r s t a n d a rd i z a t i o n c o m p ri s i n g al l n a ti o n a l e l e c t ro te c h n i c a l c o m m i t te e s (I EC N ati on a l C o m m i t te e s ) Th e ob j ect of IEC is to p ro m o t e i n t e rn a t i o n a l c o - o p e ti o n o n a l l q u e s ti o n s c o n c e rn i n g s ta n d a rd i za t i o n i n t h e e l e c tri c a l a n d e l e c tro n i c fi e l d s To th i s e n d and Te c h n i c a l in a d d i ti o n Re p o rts , t o o t h e r a c ti v i ti e s , P u b l i cl y Ava i l a b l e I EC pu bl i sh es S p e c i fi c a t i o n s I n t e rn a t i o n a l (P AS ) an d S t a n d a rd s , G u i d es Te c h n i c a l ( h e re a fte r S p e c i fi c a t i o n s , re fe rre d to as “I E C P u b l i c a t i o n ( s ) ” ) Th e i r p re p a t i o n i s e n t ru s t e d to te c h n i c a l c o m m i t te e s ; a n y I E C N a t i o n a l C o m m i tt e e i n te re s te d in th e s u b j e ct deal t wi t h m ay p a rti c i p a te in th i s p re p a t o ry wo rk I n te rn a t i o n a l , g o ve rn m e n t a l and non- g o v e rn m e n t a l o rg a n i z a t i o n s l i a i s i n g wi t h t h e I E C a l s o p a rt i c i p a t e i n th i s p re p a ti o n I E C c o l l a b o t e s c l o s e l y wi th th e I n te rn a t i o n a l O rg a n i z a t i o n fo r S ta n d a rd i z a t i o n (I S O) in a c c o rd a n c e wi t h d i ti on s d e te rm i n e d by a g re e m e n t b e t we e n t h e t wo o rg a n i za ti o n s 2) Th e fo rm a l d e c i s i o n s o r a g re e m e n ts o f I E C o n t e c h n i c a l m a t te rs e xp re s s , a s n e a rl y a s p o s s i b l e , a n i n t e rn a ti o n a l s e n s u s of opi n i on on th e re l e v a n t s u b j e cts s i n ce e a ch te c h n i c a l c o m m i tt e e h as re p re s e n ta t i o n fro m al l i n te re s t e d I E C N a t i o n a l C o m m i tt e e s 3) I E C P u b l i c a ti o n s h a ve th e fo rm o f re c o m m e n d a t i o n s fo r i n t e rn a t i o n a l u s e a n d a re a c c e p t e d by I E C N ati o n a l C o m m i tt e e s i n th a t s e n s e W h i l e a l l re a s o n a b l e e ffo rt s a re m a d e t o e n s u re th a t th e t e c h n i c a l c o n t e n t o f I E C P u bl i cati o n s is a c c u te , IEC ca n n ot be held re s p o n s i b l e fo r th e wa y in wh i c h th e y a re used or fo r any m i s i n te rp re t a t i o n b y a n y e n d u s e r 4) In o rd e r to p ro m o t e tra n s p a re n t l y to i n t e rn a t i o n a l th e m a xi m u m u n i fo rm i ty, e xt e n t I EC possi bl e in N ati on a l th e i r C o m m i tt e e s n a ti o n a l an d u n d e rta ke re g i o n a l to appl y IEC pu b l i ca ti o n s P u b l i c a ti o n s An y d i v e rg e n c e b e t we e n a n y I E C P u b l i c a t i o n a n d th e c o rre s p o n d i n g n a t i o n a l o r re g i o n a l p u b l i c a ti o n s h a l l b e c l e a rl y i n d i c a te d i n th e l a tte r 5) IEC p ro vi d e s no m a rki n g p ro c e d u re to i n d i cate i ts a p p ro v a l an d ca n n o t be re n d e re d re s p o n s i b l e fo r any e q u i p m e n t d e c l a re d t o b e i n c o n fo rm i t y wi t h a n I E C P u b l i c a ti o n 6) Al l u s e rs s h o u l d e n s u re t h a t t h e y h a v e t h e l a t e s t e d i ti o n o f t h i s p u b l i c a t i o n 7) N o l i a b i l i t y s h a l l a tta c h to I E C o r i ts d i re c t o rs , e m p l o ye e s , s e rva n t s o r a g e n ts i n c l u d i n g i n d i vi d u a l e xp e rts a n d m e m b e rs o f i t s t e c h n i c a l c o m m i t t e e s a n d I E C N a t i o n a l C o m m i t te e s fo r a n y p e rs o n a l i n j u ry , p ro p e rty d a m a g e o r oth e r d am a g e e xp e n s e s of an y a ri s i n g out n a t u re wh a ts o e v e r, wh e t h e r d i re c t of p u b l i cati on , u se th e o f, or o r i n d i re c t , re l i a n c e u pon, o r fo r c o s ts th i s I EC (i n cl u d i n g P u bl i cati o n or l eg al fe e s ) and an y oth e r IEC P u bl i cati o n s 8) At te n t i o n i s d wn t o t h e N o rm a t i ve re fe re n c e s c i t e d i n t h i s p u b l i c a ti o n U s e o f t h e re fe re n c e d p u b l i c a ti o n s i s i n d i s p e n s a b l e fo r t h e c o rre c t a p p l i c a ti o n o f t h i s p u b l i c a t i o n 9) Att e n ti o n i s d wn t o th e p o s s i b i l i t y th a t s o m e o f t h e e l e m e n ts o f th i s I E C P u b l i c a ti o n m a y b e t h e s u b j e c t o f p a te n t ri g h ts I E C s h a l l n o t b e h e l d re s p o n s i b l e fo r i d e n t i fyi n g a n y o r a l l s u c h p a t e n t ri g h ts I n te rn a ti o n a l S ta n d a rd I E C - h a s b e e n p re p a re d b y I E C te ch n i c a l c o m m i tte e : S o l i d e l e c tri ca l i n s u l a ti n g m a te ri a l s T h i s th i rd e d i ti o n c a n c e l s a n d re p l a ce s th e s e c o n d e d i ti o n p u b l i s h e d i n 9 , a n d co n s ti tu te s a te c h n i c a l re vi s i o n T h i s re vi s i o n i n c l u d e s i m p ro ve d te xt re g a rd i n g th e fl a m e te s t ( C l a u s e ) , th e i m p ro ve d te x t o n a d h e s i o n ( C l a u s e 1 ) a n d a n e w F i g u re s a a n d b T h e te x t o f th i s s ta n d a rd i s b a s e d o n th e fo l l o wi n g d o c u m e n ts : FDI S Re p o rt o n v o t i n g /3 7 /F D I S /3 /RV D F u l l i n fo rm a ti o n o n th e vo ti n g fo r th e a p p ro va l o f th i s s ta n d a rd c a n b e fo u n d i n th e re p o rt o n vo ti n g i n d i c a te d i n th e a b o ve ta b l e – – 60454-2 © I E C: 00 7(E) T h i s p u b l i c a ti o n h a s b e e n d fte d i n a cc o rd a n c e wi th th e I S O /I E C D i re cti ve s , P a rt A list of al l th e p a rts in th e I EC 60454 s e ri e s , u n d e r th e g e n e l ti tl e Pressure-sensitive adh esive ta pes for electrica l purposes , ca n b e fo u n d o n th e I E C we b s i te T h e co m m i tte e h a s d e c i d e d th a t th e co n te n ts o f th i s p u b l i c a ti o n wi l l re m a i n u n c h a n g e d u n ti l th e m a i n te n a n c e re s u l t d a te i n d i ca te d o n th e I E C we b s i te u n d e r " h ttp : //we b s to re i e c c h " i n th e d a ta re l a te d to th e s p e ci fi c p u b l i c a ti o n At th i s d a te , th e p u b l i ca ti o n wi l l b e • re co n fi rm e d ; • wi th d wn ; • re p l a ce d b y a re vi s e d e d i ti o n , o r • am en d ed A b i l i n g u a l ve rs i o n o f th i s p u b l i c a ti o n m a y b e i s s u e d a t a l a te r d a te 60454-2 © I EC: 007(E) – – P RE S S U RE -S E N S I TI VE AD H E S I VE T AP E S F O R E LE C TRI C AL P U RP O S E S – P a rt : M e th o d s o f te s t S co p e T h i s p a rt o f I E C s p e c i fi e s m e th o d s o f te s t fo r p re s s u re - s e n s i ti v e a d h e s i ve ta p e s fo r e l e c tri ca l p u rp o s e s N o rm ati ve re fe re n ce s T h e fo l l o wi n g re fe re n c e d d o c u m e n ts a re i n d i s p e n s a b l e fo r th e a p p l i c a ti o n o f th i s d o c u m e n t F o r d a te d re fe re n ce s , o n l y th e e d i ti o n ci te d a p p l i e s F o r u n d a te d re fe re n c e s , th e l a te s t e d i ti o n o f th e re fe re n c e d d o cu m e n t ( i n c l u d i n g a n y a m e n d m e n ts ) a p p l i e s I EC 6021 6-1 : 2001 , Ele ctric a l A ge in g a n d e va lu a tio n p ro c e dure s I E C 02 6-2: 200 5, D e te rm in a tio n of in s ula tin g Ele ctric a l th e rm a l m a te ria ls – Pro p e rtie s o f th e rm a l e n dura n ce – Pa rt 1: o f te s t re s u lts in s u la tin g e n dura n c e m a te ria ls p ro p e rtie s – of Th e rm a l e le ctric a l e n dura n ce in s u la tin g p ro p e rtie s m a te ria ls – – Pa rt 2: Ch o ic e of te s t crite ria I EC 6021 6-3: 2006, In s truc tio n s Ele ctric a l fo r c a lc ula tin g I EC 60243-1 : 998, in s u la tin g m a te ria ls th e rm a l e n dura n c e Ele ctric a l s tre n g th – Th e rm a l e n dura n ce p ro p e rtie s – Pa rt 3: c h a cte ris tics o f in s ula tin g m a te ria ls – Te s t m e th o ds – Pa rt : Te s ts a t p o we r fre q ue n c ie s I EC 6042 6: 007, Te s t m e th o ds I E C - ( a l l p a rts ) , S p e c ific a tio n s Me th o ds m a te ria ls I SO 383: 976, of te s t b y e xtra c tio n a dh e s ive co rro s io n ta p e s fo r with in s ula tin g e le ctric a l m a te ria ls p urp o s e s – Pa rt 3: Pla s tic s – th e de te rm in a tio n of io n ic im p uritie s in e le ctric a l liq uids – In te rch a n g e a b le D e te rm in a tio n of te n s ile c o n ic a l gro un d jo in ts p ro p e rtie s – Pa rt 3: Te s t c o n ditio n s fo r a n d s h e e ts I SO 21 94: 991 , sh e e t – In dus tria l D e s ig n a tio n s cre e n s Te xtile s I SO 3599: 976, Ve rn ie r c a llip e rs I SO 0093: 998, 939: 2003, – Wo ve n a n d n o m in a l s ize s I SO 307 : 00 5, EN fo r with L a b o to ry g la s s wa re I S O 52 7-3: 995, film s Pre s s ure - s e n s itive e le ctro lytic fo r in dividua l m a te ria ls I EC 60589: 977, in s u la tin g fo r de te rm in in g – Pla s tics D e te rm in a tio n – Fire Se lf- a dh e s ive ta p e s – − clo th , o f p H o f th e re a din g to te s ts wire p e rfo te d p la ce and e le c tro fo rm e d o f o p e n in g s 0, a q ue o us e xtra ct a n d 0, 05 m m S ta n da rd ign itio n s o urc e s D e te rm in a tio n peel of a dh e s io n p ro p e rtie s (Th e peel a d h e s i o n te s t m e th o d o f C l a u s e 1 i s b a s e d o n te s t m e th o d A o f E N 9 : 0 T h i s s ta n d a rd is th e re s u l t o f th e h a rm o n i s a ti o n o f AF E RA 0 and PSTC-1 , , an d 4, AS T M 3 /D , AS T M 3 /M a n d a g re e d b y J AT M A ) N O TE E N : E u ro p e a n N o rm ( E u ro p e ) − AF E RA: As s o c i a t i o n d e s fa b ri c a n t s e u ro p é e n s d e ru b a n s a u to - a d h é s i fs P S T C : P re s s u re s e n s i ti ve ta p e c o u n c i l ( U S A ) − AS T M : Am e ri c a n s o c i e t y fo r t e s t i n g a n d m a t e ri a l s ( U S A ) J a p a n e s e a d h e s i ve t a p e s m a n u fa c tu re rs a s s o c i a t i o n − − J AT M A: –8– C o n d i ti o n i n g a n d s p e ci m e n 60454-2 © IEC:2007(E) p re p a t i o n Unless otherwise specified, rolls are to be conditioned for at least 24 h at (23 ± 2) °C and (50 ± 5) % relative humidity and all test procedures are to be carried out in this atmosphere Remove and discard the three outer turns before taking any test specimens from the conditioned roll Specimen preparation shall be done with care in a clean environment Specific specimen preparation details will be included with the appropriate test method Further conditioning of test specimens may be required D e t e rm i n a t i o n o f t h i c kn e s s T e s t a p p a t u s A dead-weight thickness gauge having two ground and concentric circular surfaces, flat within 0,001 mm and parallel to within 0,003 mm The upper surface shall be mm to mm in diameter and the lower surface larger than the upper one The upper surface shall move on the axis perpendicular to the two faces The gauge shall be graduated to read directly to 0,002 mm The frame of the thickness gauge shall be of such rigidity that a load of N applied to the gauge housing, out of contact with either the weight or the pressure foot spindle, will produce a deflection of the frame not greater than 0,002 mm (as indicated on the thickness gauge) The pressure exerted on the specimen shall be (50 ± 5) kPa The accuracy of the thickness gauge shall be checked frequently by means of a set of steel gauges; the measuring errors of the thickness gauge shall not exceed 0,005 mm Test speci m en s Five specimens, at least 75 mm long, are cut from the roll at intervals not less than 300 mm The specimen shall be allowed to relax for at least P ro c e d u re Place the test specimen between the jaws of the thickness gauge in contact with the fixed foot Take care to ensure that no air bubbles are trapped Lower the moving pressure foot gently on to the surface of the tape and take the reading on the gauge within s Read the measurement to the nearest 0,002 mm on the thickness gauge scale 4 Re s u l t s Report the central value as well as the maximum and minimum values of the five readings of thickness in millimetres D e t e rm i n a t i o n M eth o d o f w i d th A Use a steel rule graduated to 0,5 mm The total measuring error of the rule shall not exceed 0,1 mm A specimen of tape, at least 450 mm long, is removed from the roll and placed adhesive side up on a smooth flat surface The specimen shall be allowed to relax for at least