I E C TS 60079-32 -1 ® Edition 1 201 7-03 CON SOLI D ATED VE R SI ON colour i n si de E xpl o si ve atm osph eres – IEC TS 60079-32-1 :201 3-08+AMD1 :201 7-03 CSV(en) Part 32 -1 : E l ectro stati c h azard s, g u i d an ce TH I S P U B L I C AT I O N I S C O P Y R I G H T P R O T E C T E D C o p yri g h t © I E C , G e n e v a , Sw i t z e rl a n d All rights reserved Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IEC or IEC's member National Committee in the country of the requester If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or your local IEC member National Committee for further information IEC Central Office 3, rue de Varembé CH-1 21 Geneva 20 Switzerland Tel.: +41 22 91 02 1 Fax: +41 22 91 03 00 info@iec.ch www.iec.ch Ab o u t th e I E C The International Electrotechnical Commission (I EC) is the leading global organization that prepares and publishes International Standards for all electrical, electronic and related technologies Ab o u t I E C p u b l i ca t i o n s The technical content of IEC publications is kept under constant review by the IEC Please make sure that you have the latest edition, a corrigenda or an amendment might have been published I E C Catal o g u e - websto re i ec ch /catal o g u e The stand-alone application for consulting the entire bibliographical information on IEC International Standards, Technical Specifications, Technical Reports and other documents Available for PC, Mac OS, Android Tablets and iPad I E C pu bl i cati on s search - www i ec ch /search pu b The advanced search enables to find IEC publications by a variety of criteria (reference number, text, technical committee,…) It also gives information on projects, replaced and withdrawn publications E l ectroped i a - www el ectro ped i a o rg The world's leading online dictionary of electronic and electrical terms containing 20 000 terms and definitions in English and French, with equivalent terms in additional languages Also known as the International Electrotechnical Vocabulary (IEV) online I E C G l o ssary - std i ec ch /g l o ssary 65 000 electrotechnical terminology entries in English and French extracted from the Terms and Definitions clause of IEC publications issued since 2002 Some entries have been collected from earlier publications of IEC TC 37, 77, 86 and CISPR I E C J u st Pu bl i sh ed - websto re i ec ch /j u stpu bl i sh ed Stay up to date on all new IEC publications Just Published details all new publications released Available online and also once a month by email I E C Cu stom er Servi ce Cen tre - websto re i ec ch /csc If you wish to give us your feedback on this publication or need further assistance, please contact the Customer Service Centre: csc@iec.ch I E C TS 60079-32 -1 ® Edition 1 201 7-03 CON SOLI D ATED VE R SI ON colour i n si de E xpl osi ve atm osph eres – Part 32 -1 : E l ectrostati c h azard s, g u i d an ce INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 29.260.20 ISBN 978-2-8322-41 21 -9 Warn i n g ! M ake su re th a t yo u o btai n ed th i s pu bl i c ati o n fro m an au th ori zed d i stri bu to r ® Registered trademark of the International Electrotechnical Commission I E C TS 60079-32 -1 ® Edition 1 201 7-03 R E DLI N E VE R SI ON colour i n si de E xpl o si ve atm osph eres – IEC TS 60079-32-1 :201 3-08+AMD1 :201 7-03 CSV(en) Part 32 -1 : E l ectro stati c h azard s, g u i d an ce – – I EC TS 60079-32-1 :201 3+AMD1 :201 CSV © I EC 201 CONTENTS FOREWORD 1 I NTRODUCTI ON Scope N orm ati ve references Term s and defi n i ti ons N om enclature 20 General 21 Static el ectrici ty i n sol id m aterials 22 General considerati ons 22 The use of ducti ve or dissi pati ve m aterials in pl ace of i nsu latin g ones 24 G eneral considerati ons 24 2 Dissipati ve soli d m ateri al s 24 Earth in g of conducti ve and dissi pati ve item s 25 Precau tions requ ired wh en u si n g i nsu lati n g solid m aterials 26 G eneral 26 Restricti ons on th e si ze of charg eabl e insu l atin g surfaces 27 3 Earth ed m etal m eshes 28 I nsu latin g coati n gs on earth ed ducti ve surfaces 28 Con ducti ve or dissi pative coati n g s on insu lati ng m aterials 29 6 Static dissi pative agents 30 H um idification 30 I on isation / Charg e N eu tralisati on 30 Methods to determ in e th e i ncen di vity of disch arges 31 Con veyor bel ts an d transm ission belts 32 G eneral 32 Con veyor bel ts 32 Transm issi on bel ts 33 Static el ectricity in l iqu i ds 34 General considerati ons 34 Occurrence of flam m abl e atm osph eres 34 I g n iti on sensiti vi ty and li m itati ons to the scope of advice 35 Ch argi n g m ech an ism s 36 Ch arge accum u lati on an d conducti vi ty cl assificati ons 36 I ncendi ve disch arg es produced du rin g li qu id h an dl i ng operati ons 37 Sum m ary of precautions ag nst i g n ition h azards duri n g l iqu i d h an dlin g operations 38 Earth in g an d avoidance of isol ated ductors 38 2 Restricti ng ch arg e gen erati on 38 Avoi dance of a fl am m abl e atm osph ere 39 Prom oti n g ch arg e dissipati on 39 Tanks an d Contain ers 39 G eneral 39 Con ducti ve tanks an d contain ers 40 3 Tanks an d contai ners m ade en tirel y of dissipative m aterial 53 Tanks an d contai ners wi th i nsu latin g surfaces 53 I EC TS 60079-32-1 : 201 3+AMD1 :201 CSV – – © I EC 201 U se of li ners i n tai n ers 57 Hi g h viscosity l i qui ds 58 Hi g h ch arg in g equ i pm ent 58 Fi lters, water separators an d strain ers 58 Pum ps an d oth er equ i pm en t 59 Gau g i ng an d sam pli n g i n tanks 60 G eneral 60 Precau ti ons durin g g au g i ng an d sam pli n g 60 7 Pipes an d h ose assem bli es for liqu ids 61 7 G eneral 61 7 Pipes 61 7 H oses and hose assem bli es 64 Special fi l li ng procedures 70 Aircraft fu el lin g 70 Road tanker del i veries 71 Retai l fi l li n g stations 72 Mobi le or tem porary l iqu i d h an dlin g equ i pm en t 76 Plan t processes (bl en di n g, stirri ng , m ixin g , crystall isation an d sti rred reactors) 76 G eneral 76 Earth in g 76 I n-l i ne bl endin g 76 Blen din g i n vessels or tanks 77 J et m ixi ng 77 H i g h speed m ixi ng 78 Sprayin g liqu ids and tank clean i n g 78 1 G eneral 78 Tank clean i ng with low or m edi um pressu re water j ets (u p to about bar) 78 Tank clean i ng with low ducti vity l i qu ids 79 Tank clean i ng with h ig h pressure water or solven t j ets (above bar) 79 Steam cl ean in g tanks 79 Water delu g e system s 80 1 Gl ass system s 80 1 G eneral 80 1 Precau ti ons to be taken for l ow ducti vity l i qu ids 80 Static el ectrici ty i n g ases 81 General 81 Gri t blastin g 81 Fire exti n gu ish ers 82 I n erti n g 82 Steam cl ean in g 82 Accidental l eakag e of com pressed gas 82 Sprayin g of fl am m abl e pain ts and powders 83 G eneral 83 Earth in g 83 Plastic spray cabi n ets 83 8 Vacu um cl ean ers, fixed and m obi le 83 – – I EC TS 60079-32-1 :201 3+AMD1 :201 CSV © I EC 201 10 11 12 8 G eneral 83 8 Fixed system s 83 8 Portable system s 84 8 Vacu u m trucks 84 Static el ectrici ty i n powders 84 General 84 Disch arges, occurrence an d i ncen di vity 85 Procedu ral m easures 86 G eneral 86 H um idification 86 3 H oses for pn eum atic tran sfer 86 I on isation 86 Bulk m ateri als in the absence of flam m abl e gases an d vapours 87 G eneral 87 Equ ipm ent an d obj ects m ade of conducti ve or dissi pati ve m aterials 87 Equ ipm ent an d obj ects m ade of i nsu l ati n g m aterial s 87 4 Dust separators 88 Si los an d Con tai n ers 88 Addi ti on al requ irem ents for bulk m aterial i n the presence of fl am m able gases an d vapours 94 G eneral 94 Measures for resisti vity g reater equ al 00 M Ω m 94 Measures for resisti vity l ess th an 00 M Ω m 94 Fi l l in g of bulk m ateri al i nto a contain er 95 Fl exibl e interm ediate bu l k contai ners (FI BC) 96 G eneral 96 Additi on al precauti ons when u si ng FI BC 98 Static el ectrici ty wh en h andl ing expl osi ves an d el ectro-explosi ve devices 99 1 Expl osi ves m an u facture, han dli n g and storag e 99 1 G eneral 99 1 First degree protection 99 1 I n term ediate protection 99 1 Secon d degree protecti on 99 Han dl i n g of el ectro-explosive devices 00 G eneral 00 2 Earth in g 00 Precau ti ons durin g storage an d issu e 01 Precau ti ons durin g preparation for use 01 Static el ectrici ty on peopl e 01 1 General considerati ons 01 1 Static dissi pati ve floors 02 1 Dissi pati ve an d ducti ve footwear 02 1 Supplem entary devices for earth in g of people 03 1 Cl oth i ng 03 1 Gl oves 05 1 Oth er I tem s 05 Electrostatic sh ock 05 I n troducti on 05 I EC TS 60079-32-1 : 201 3+AMD1 :201 CSV – – © I EC 201 2 Disch arges rel evan t to electrostatic shocks 06 Sources of electrostatic shock 06 Precau tions to avoi d el ectrostatic sh ocks 07 Sou rces of electrostatic shocks 07 Reported shocks from equ ipm en t or processes 07 Shocks as a resul t of people bei ng ch arg ed 07 Precau tions i n speci al cases 08 Pneum atic veyi n g 08 Vacu u m cl ean ers 08 Reels of charg ed film or sheet 08 Fire exti n g u ish ers 09 Earth in g an d bon din g 09 General 09 Cri teria for the dissi pati on of static electrici ty from a ductor 1 Basic consi derations 1 2 Practical criteria 1 3 Earth in g requ irem en ts i n practical system s 1 3 Al l-m etal system s 1 3 Metal plant with insu l atin g parts 1 3 3 I nsu latin g m ateri als 1 3 Con ducti ve an d dissipati ve m aterials 1 3 Earth in g via i n trinsic safety circui ts 1 3 Earth in g of sh ips 1 The establishm en t an d m on i tori n g of earth in g system s 1 Desig n 1 Mon itoring 1 Speci al requ irem ents for equ i pm ent accordin g to I EC 60079-0 1 General 1 Electrostatic ch arges on external n on-m etal l ic m aterials 1 Applicabi l ity 1 2 Avoi dance of a bu il d-u p of electrostatic charg e on Grou p I or G roup I I electrical equ ipm ent 1 Avoi dance of a bu il d-u p of electrostatic charg e on equi pm en t for G rou p I I I 20 Electrostatic ch arges on external du cti ve parts 20 Ann ex A (inform ati ve) Fun dam entals of static electricity 21 A Electrostatic ch arg in g 21 A I n troducti on 21 A Contact charg i ng 21 A Contact charg i ng of l iqui ds 21 A Ch arge gen eration on li qu ids fl owing in pi pes 22 A Ch arge gen eration i n fi lters 25 A Ch arge gen eration durin g stirrin g and m ixin g of li qu ids 25 A Settl i n g poten tials 25 A Breaku p of liqu id j ets 25 A Contact charg i ng of powders 25 A Ch argi n g by i n duction 26 A 1 Ch arge transfer by du ction 26 A Ch argi n g by corona discharg e 26 – – I EC TS 60079-32-1 :201 3+AMD1 :201 CSV © I EC 201 A A A Ann ex B B B B Ann ex C C C C C C C C C Ann ex D D D D Accum u lati on of el ectrostatic ch arg e 26 A G eneral 26 A 2 Ch arge accum ul ation on l iqu ids 27 A Ch arge accum ul ation on powders 28 Electrostatic disch arg es 29 A I n troducti on 29 A Sparks 29 A 3 Corona 30 A Brush disch arges 30 A Propagatin g bru sh disch arg es 31 A Lig htn ing like disch arg es 31 A Con e disch arges 32 Measurem ents for risk assessm ent 32 (inform ati ve) Electrostatic disch arg es in specific situ ations 34 I ncendi ve disch arg es i n vol vi n g i nsu l ati n g sol id m ateri als 34 B G eneral 34 B Sparks from isolated du ctors 34 B Brush disch arges from i n su latin g sol id m ateri als 34 B Propag atin g brush disch arg es from i nsu l atin g solid m aterials 34 I ncendi ve disch arg es produced durin g l iqu i d h an dli ng 35 B G eneral 35 B 2 Calcu lated m axim um safe flow veloci ties for fi lli n g m edi um sized vertical axis storag e tanks 35 I ncendi ve disch arg es produ ced durin g powder h an dli n g and storag e 37 B G eneral 37 B Disch arges from bulk powder 37 B 3 Disch arges from powder cl ou ds 37 B Disch arges in vol vin g i nsu latin g contain ers an d peopl e 37 B The u se of l i n ers i n powder processes 37 B Spark disch arges in powder processes 38 B Brush disch arges in powder processes 38 B Corona disch arg es in powder processes 38 B Propag atin g brush disch arg es in powder processes 38 (inform ative) Flam m abil i ty properti es of substances 40 General 40 Effect of oxyg en concen tration an d am bient ditions 40 Expl osi ve l im its for g ases an d liqu ids 40 I n erti n g 40 Fl ash point 41 M in im um ig n iti on en erg ies 41 Com bustible powders 44 Biofuels 44 (inform ative) Cl assificati on of h azardou s areas 45 Concept of zon i ng 45 Cl assificati on 45 Expl osi on grou ps 45 D G eneral 45 D G roup I 45 D 3 G roup I I 46 C.vT.Bg.Jy.Lj.Tai lieu Luan vT.Bg.Jy.Lj van Luan an.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an – 66 – I EC TS 60079-32-1 :201 3+AMD1 :201 CSV © I EC 201 beads assist i n th e m ixi n g of th e g ases and also tribu te to preven tin g propag ation of an y flam e back throu g h th e probe An adj ustable shroud m ade from i nsu l ati n g m ateri al is fi tted to the cyli n der to direct gas over th e disch arg e el ectrode an d i n to th e reg i on i n fron t of the disch arg e el ectrode wh ere electrostatic discharg es take place The openin g i n th is shroud is (40 ± 5) m m The flam m abl e g as is g enerated by m ixing th e test g as (m in im um 99, % puri ty) wi th air Th e air used sh ou ld tai n (21 , ± 0, 5) % oxyg en an d (79, ± 0, 5) % n itrog en Th e g as trol an d m ixin g apparatus is used to direct the g as in th e appropriate proporti ons to th e ig n iti on probe The vol um e concentrati ons of th e test g as used are sh own i n Table G Table G.1 – Volume concentrations of flammable g as mixtu res Test g as Volume concentration Minimum ignition energ ya Explosion group H ydrog en (22, ± 0, 3) % i n r 0, 01 m J IIC Ethyl en e (8, ± 0, ) % i n r 0, 082 m J IIB (5, ± 0, ) % i n r 0, 25 m J IIA Propane b a See C b See EN 50050 The control of th e g as m ixture with in th e specifi ed tol erances sh ou l d be checked usi n g, for exam ple, an i nfra-red g as an al yzer sam pli n g th e gas m ixtu re suppl y li ne I f a gas m ixture other th an th at specified in Tabl e G is used, the m in im um ig ni tion en erg y of th e g as m ixtu re sh ou l d be verified u sin g the ASTM E582- 88 m ethod I t is ven ien t to use com pressed gas cyl i n ders for the gas su ppl y, bu t other sou rces of suppl y m ay be u sed I f n ecessary, m olecu lar sieve fil ters sh ou ld be used to ensure the gases have l ow m oistu re content This is particu larl y im portan t, for exam pl e, wh en usi ng air directl y from a com pressor Each gas suppl y is troll ed an d m on itored u si ng fl owm eters an d val ves The com bi ned flow-rate of al l g ases throug h the ig n ition probe sh ou ld be (0, 21 ± 0, 04) l/s A fast acti on sh u t-off val ve is used to stop th e flow of test gas wh en i g n iti on occurs Th e sh utoff val ve sh ou ld stop th e su ppl y of test g as wh ilst leavin g th e air to flow freel y to provide cool i ng an d dryi n g of th e i g ni tion probe after i gn i tion h as occurred Th e type an d location of th e sh ut-off val ve shou ld be sel ected as appropriate to th e specific desi gn of th e overal l apparatus Stt.010.Mssv.BKD002ac.email.ninhd.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj.dtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.vT.Bg.Jy.Lj.Tai lieu Luan vT.Bg.Jy.Lj van Luan an.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an I EC TS 60079-32-1 : 201 3+AMD1 :201 CSV – 67 – © I EC 201 ∅ 40 ± ∅ 20 ± 35 ± 5 00 ± 5 ∅ 70 ± IEC 2183/13 Dimensions in millimetres Ke y di sch arg e el ectrode adj u stabl e sh roud m ade from i nsul ati n g m ateri al (e g pol ycarbonate or acryl i c) cyl i n d er m ade from i nsu l ati n g m ateri al (e g pol ycarbon ate or acryl i c) perforated m etal pl ate (2m m nom i n al th i ckn ess) fi n e m etal m esh or g au ze (e g copper) beads (e g g l ass or porcel n) , –2 m m di am eter (n om i nal ) robust earth n ecti on earth n ector i nl et port for fl am m abl e g as Fi g u re G – I g n i ti o n p robe Stt.010.Mssv.BKD002ac.email.ninhd.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj.dtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.vT.Bg.Jy.Lj.Tai lieu Luan vT.Bg.Jy.Lj van Luan an.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an – 68 – I EC TS 60079-32-1 :201 3+AMD1 : 201 CSV © I EC 201 20 ± 35 ± 50 ± IEC 2184/13 Dimensions in millimetres Key perforati on (5 ± ) m m di am eter m oun ti n g h ol e for di sch arg e el ectrode screw for securi n g pl ate to bod y of i g ni ti on probe Figure G.5 – Perforated plate of ignition probe G.1 Procedure I g n iti on tests are carri ed out by bri ng in g th e ig n iti on probe cl ose to th e charg ed test sam pl e wi th the fl am m abl e g as m ixture flowi n g throug h the probe The sam e test procedure as described i n G 4, steps to 6, sh ou ld be execu ted except th at th e num bers of test sequ ences sh oul d at least be dou bled to com pensate statistical scatters G.1 Acceptance criteria An y ig n iti on occurring sh ou ld be reg arded as product fai lure for th e explosi on grou p g iven by th e specific g as m ixtu re Ch arg in g by coron a an d whi ppin g with a l eather g love are strong charg e g eneratin g processes com parabl e to m achin e rubbi ng , ch arg in g by el ectrons i n th e vici n ity of i onisers an d el ectrostatic sprayi n g equ i pm ent or charg i ng by stream in g l iqui ds an d powders G.1 Test report The test report sh ou l d i n cl ude at l east th e followi n g i nform ation : – – – – – – m easurin g l aboratory, date of m easu rem en t, tem perature an d relative hum i di ty, descri pti on and identification of th e sam pl e, type of cl othes used, coron a voltage, Stt.010.Mssv.BKD002ac.email.ninhd.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj.dtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.vT.Bg.Jy.Lj.Tai lieu Luan vT.Bg.Jy.Lj van Luan an.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an I EC TS 60079-32-1 :201 3+AMD1 : 201 CSV – 69 – © I EC 201 – – – – – – ig n i ti on test resu lts, num ber of n on i gn i tions obtain ed, i gn ition was obtain ed wi th th e reference sam ple, i dentification of th e used i nstrum entati on, date of its m ost recen t as well as its next ch eck, num ber of th is standard G.1 Measuring of charge decay G.1 2.1 General Anoth er possi bi l ity to evalu ate th e charg eabi l ity of a m ateri al, and one that is preferable for garm ents, is m easuri ng of its ch arg e decay according to I EC 61 340-2-1 NOTE I n Eu rope, th e m ethod descri bed i n EN 1 49-3 i s used to determ i n e charg e decay from person n el protecti ve cl oth i n g G.1 2.2 Principle The m ateri al is ch arged by corona and the decay of its su rface equ ival ent voltag e, m easured wi th a fiel d m eter, is recorded i n between a g iven voltag e i n terval G.1 2.3 Apparatus An exam pl e of th e apparatu s is sh own i n Fi gure G The test aperture for deposition an d m easurem ent of deposi ted ch arge sh ou ld be 50 m m diam eter or an equ i valent area qu asi squ are apertu re All the coron a poi nts are m ou n ted i n a m m diam eter circle on a m ovable plate m m above th e cen tre of th e test apertu re The fiel dm eter sensin g apertu re sh ou ld be 25 m m above th e cen tre of th e test area When th e plate wi th th e corona poin ts is m oved fu l l y away, th e test area shou ld be clear u p to th e plan e of th e fieldm eter sensi n g apertu re The fi el d m eter shou ld be a fiel d-m il l type of instrum ent able to m easure th e su rface vol tag e wi th an accuracy of V to below 40 V with a respon d tim e (1 % to 90 %) bel ow m s The stabi li ty of zero shou l d all ow m easurem ents of surface voltage wi th th is accuracy over th e lon g est decay tim es to be m easured An y rest ion i zati on in th e m easu ri ng cham ber shou l d be less th an V wh ich can be evalu ated wi th fu l l y ducti ve g arm ents The field m eter sh ou l d be n ected to a Person al Com puter or an osci l loscope to record charg e decay NOTE M ore detai l s abou t th i s m easu ri n g procedu re and d rawi n g s of the n ecessary apparatus can be fou nd i n I EC 61 340-2-1 Stt.010.Mssv.BKD002ac.email.ninhd.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj.dtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.vT.Bg.Jy.Lj.Tai lieu Luan vT.Bg.Jy.Lj van Luan an.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an – 70 – I EC TS 60079-32-1 :201 3+AMD1 :201 CSV © I EC 201 Dimensions in millimetres Key 1 m m di am eter ci rcl e of coron a poi nts Fi el dm eter sen si ng apertu re Movabl e pl ate: – i nsul ati ng pl ate: to m oun t corona poi nts (resi stance to g rou n d > 1 Ω) – earthed top su rface: to shi el d fi el dm eter Earth ed casi ng Sam pl e Open -sh i el ded backi n g NOTE Al l di m ensi on s are n om i n al Figure G.6 – Example of an arrang ement for measurement of charg e decay G.1 2.4 Test sample The sam ple is typical l y a garm ent m aterial of at least 60 m m in di am eter Rem ove an y l oose dust by gentl y brushi n g or bl owin g with clean air Furth er cl ean i ng sh oul d on l y be don e if th is is agreed to H owever, n ot test obvi ousl y contam in ated parts The atm osph ere for diti on i ng an d testin g sh ou ld be (23 ± 2) °C and (25 ± 5) % relati ve hu m i di ty The diti on i ng tim e pri or to th e testi ng sh ou ld be at least 48 h , or as oth erwise ag reed G.1 2.5 Procedure The test procedure is as fol l ows: a) Cl am p th e g arm ent in th e apparatus b) Move the m iddle plate so that th e corona points are effecti vel y pl aced an d the fi eld m eter is sh ielded Stt.010.Mssv.BKD002ac.email.ninhd.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj.dtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.vT.Bg.Jy.Lj.Tai lieu Luan vT.Bg.Jy.Lj van Luan an.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an I EC TS 60079-32-1 : 201 3+AMD1 :201 CSV – 71 – © I EC 201 c) Appl y kV to kV neg ati ve on the coron a poi nts for (1 ± 0, 5) secon ds d) Rem ove the m i ddle plate so that th e field m eter can m easure th e equ ival en t surface poten tial of th e probe e) Measure th e ch arge decay from th e i n iti al voltag e to th e agreed lower vol tag e level f) Repeat steps b) to e) two tim es on differen t l ocations g) Repeat steps a) to f) with positive pol arity G.1 2.6 Acceptance criteria Acceptabl e decay tim e i s depen dent on the charg in g processes i n vol ved in the applicati on For m an ual processes wh ere ch argin g is dependent on h u m an acti vi ty, a decay tim e from 000 V to 00 V in about s to s is gen eral l y acceptabl e Where ch arg in g currents are hig h er, sh orter decay tim es m ay be requ ired G.1 2.7 Test report The test report sh ou l d in cl ude at l east th e foll owin g i nform ation : – – – – – – – – – – m easurin g l aboratory, date of m easu rem en t, tem perature an d relati ve hum idity, descri pti on and identificati on of th e sam pl e, test resul ts, appl ied corona vol tag e charg i ng tim e, i dentification of th e u sed i nstru m entati on, date of its m ost recen t as well as its next calibrati on, num ber of th is stan dard G.1 Breakthrough voltage G.1 3.1 General The electrical breakthroug h vol tag e sh ou ld be m easured accordi ng to the sh ort-tim e (rapid rise) test i n I EC 60243-1 wi th th e addi tion al requ irem ents of I EC 60243-2 for DC testi n g G.1 3.2 Principle The test sam pl e is placed between two m etal electrodes A DC voltag e is applied and increased u n til breakthroug h occurs G.1 3.3 Apparatus I n cases of plates, discs and sh eets, the sam pl e is pl aced between two m etal cyl i n ders Accordi n g to I EC 60243-1 , th e first is (25 ± ) m m in di am eter, (25 ± ) m m in h eig h t, pressed with kg on the sam ple, an d th e second on e (75 ± ) m m in di am eter, (1 ± ) m m in h eig h t (Fi g ure G 7) Th e edg es of th e m etal cyli n ders shou ld be roun ded with a radiu s of (3 ± 0, 2) m m to avoi d coron a discharg es I n the case of sm al l hoses the el ectrodes sh ou ld be a m etal rod cl osel y in tact with the insi de of the hose and a m etal foil tape at the ou ter side of the specim en Stt.010.Mssv.BKD002ac.email.ninhd.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj.dtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.vT.Bg.Jy.Lj.Tai lieu Luan vT.Bg.Jy.Lj van Luan an.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an – 72 – I EC TS 60079-32-1 :201 3+AMD1 :201 CSV © I EC 201 ∅ 25 R3 Metal ≈ 25 ∅6 R3 R3 ∅ 75 ≈ 15 R3 Electrode support IEC 2186/13 Dimensions in millimetres Figure G.7 – Electrodes for measuring breakthrough voltag e of sheets The electrodes are nected to a DC H V g enerator wi th cal i brated voltag e an d cu rrent displ ays For n orm al electrostatic pu rposes, a m axim u m voltag e of 20 kV is suffici ent H owever, i n th e case of tube testi ng a m axim um voltag e of 20 kV is n ecessary G.1 3.4 Test procedure The test procedure is as foll ows: a) Acclim ate th e sam pl es at (23 ± 2) °C an d (25 ± 5) % relati ve hum i di ty except when other diti ons have been agreed b) Place a sam ple between th e el ectrodes in th e sam e cl im ate c) Appl y a DC voltag e between th e electrodes an d slowl y increase it from V at a rate of 00 V/s d) M onitor th e current m on i tored throug h th is procedu re e) Stop th e test an d record th e actu al voltag e if either a rapi d increase of cu rrent, often tog ether wi th a ban g an d sm oke, occurred, or an agreed u pper l im it of th e curren t is reach ed f) I f th e outpu t current of the DC power suppl y reaches m A before th e electrode voltag e reach es kV (6 kV in case of fabrics) , th e m ateri al un der test sh ou ld be deem ed to h ave a sufficient low breakthroug h vol tag e NOTE G.1 3.5 M ore detai l s abou t th i s m easuri n g procedu re can be fou n d i n I EC 60243-1 an d I EC 60243-2 Acceptance criteria The m axim um allowed valu e depen ds on th e type of th e h azardous area an d is g i ven i n an d G.1 3.6 Test report The test report sh ou ld i n clude at least th e foll owi n g inform ation : – – – m easurin g laboratory, date of m easu rem en t, tem perature an d relati ve hu m i di ty, Stt.010.Mssv.BKD002ac.email.ninhd.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj.dtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.vT.Bg.Jy.Lj.Tai lieu Luan vT.Bg.Jy.Lj van Luan an.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an I EC TS 60079-32-1 : 201 3+AMD1 :201 CSV – 73 – © I EC 201 – – – – – descri pti on and identificati on of th e sam pl e, m edi an breakthroug h voltag e or reach in g m A l im it, wh atever is appl icabl e i dentification of th e used i nstru m entation, date of its m ost recen t as well as its next calibrati on, num ber of th is stan dard Stt.010.Mssv.BKD002ac.email.ninhd.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj.dtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.vT.Bg.Jy.Lj.Tai lieu Luan vT.Bg.Jy.Lj van Luan an.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an – 74 – I EC TS 60079-32-1 :201 3+AMD1 :201 CSV © I EC 201 Bibliograph y Electrical strength of insulating materials – Test methods – Part 1: Tests at power frequencies I EC 60243-1 , Electric strength of insulating materials – Test methods – Part 2: Additional requirements for tests using direct voltage I EC 60243-2, IEC 60247, Insulating liquids – Measurement of relative permittivity, dielectric dissipation factor (tan d) and d.c resistivity IEC 61 241 -2-3, Electrical apparatus for use in the presence of combustible dust – Part 2: Test methods – Section 3: Method for determining minimum ignition energy of dust/air mixtures IEC 61 340-2-1 , Electrostatics – Part 2-1: Measurement methods – Ability of materials and products to dissipate static electric charge Electrostatics – Part 4-5: Standard test methods for specific applications – Methods for characterizing the electrostatic protection of footwear and flooring in combination with a person IEC 61 340-4-5, IEC 61 340-4-7, Ionization Electrostatics – Part 4-7: Standard test methods for specific applications – IEC/TS 61 241 -2-2, Electrical apparatus for use in the presence of combustible dust – Part 2: Test methods – Section 2: Method for determining the electrical resistivity of dust in layers IEC/TR 61 340-1 , measurements Electrostatics – Part 1: Electrostatic phenomena – Principles and ISO 81 3, Belt drives – V-ribbed belts, joined V-belts and V-belts including wide section belts and hexagonal belts – Electrical conductivity of antistatic belts: Characteristics and methods of test ISO 8028, Rubber and/or plastics hoses and hose assemblies for airless paint spraying – Specification ISO 8330, Rubber and plastics hoses and hose assemblies – Vocabulary ISO 0965, Textile floor coverings – determination of electrical resistance ISO 3688, Protective clothing – General requirements I SO 20344, Personal protective equipment – Test methods for footwear I SO 20345, Personal protective equipment – Safety footwear API /I P RP 540, Design, Construction, Operation and Maintenance of Aviation Fuelling ASTM D2624-07a, Standard Test Methods for Electrical Conductivity of Aviation and Distillate Facilities Fuels CEN ELEC TR 50404, Code of practice for the avoidance of hazards due to static electricity Stt.010.Mssv.BKD002ac.email.ninhd.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj.dtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.vT.Bg.Jy.Lj.Tai lieu Luan vT.Bg.Jy.Lj van Luan an.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an I EC TS 60079-32-1 : 201 3+AMD1 :201 CSV – 75 – © I EC 201 Testing of textiles; electrostatic behavior; determination of electrical resistance of strips of textile fabrics DI N 54345-5, EC Directi ve 89/686/EEC, Personal Protective Equipment Minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres EC Directi ve 99/92/EC, Protecting clothes – Electrostatic properties – Part 1: Test method for measuring the surface resistivity EN 1 49-1 , Protecting clothes – Electrostatic properties – Part 2: Test method for measuring the volume resistivity EN 1 49-2, EN 3821 , Potentially explosive atmospheres – Explosion prevention and protection – Determination of minimum ignition energy of dust/air mixtures EN 50050, Electrical apparatus for potentially explosive atmospheres – Electrostatic handheld spraying equipment Specification for electrostatic hand-held spraying equipment for non-flammable material for painting and finishing EN 50059, EN 501 76, Automatic electrostatic spraying installations for flammable liquid spraying material EN 501 77, Automatic electrostatic spraying installations for flammable coating powder EN 50223, Automatic electrostatic spraying installations for flammable flock material NFPA 69, Standard on explosion prevention systems NFPA 484, Standard for combustible metal TRBS 21 53 , Avoidance of ignition hazards due to static electricity Edi tor: Berufsgen ossenschaft der Ch em isch en I n dustri e, Heidelberg , Germ an y (avail able i n Germ an on l y) BI A-Report 2/97: Burning and explosion characteristics of dusts , 997 (in Germ an lan g u ag e on l y) Edi tor: H auptverban d der g ewerbl ich en Berufsg en ossenschaften e V , St Au g u stin, Germ an y G L H earn , Electrostatic ignition Preven tion, 5, (2002) , 05-1 09 hazards arising from fuel flow in plastic pipelines , H L Walm sley, The generation of electric currents by the Long pipes, J Ph ys D Appl Ph ys, 5, (1 982) , 907-1 934 J Loss turbulent flow of dielectric liquids: Electrostatic Ignition Hazards in Road Tanker Loading: Part 1, Review and Experimental Measurements, J Electrostatics, 28, (1 992) , 61 -87 H L Walm sley an d J M il ls, H L Walm sley, The electrostatic fields and potentials generated by the flow of liquid through plastic pipes J ourn al of Electrostatics 38 (1 996) , 249-266 ————————— Th i s docu m en t su persed es BG R 32:2004 an d ZH /200: 989 Stt.010.Mssv.BKD002ac.email.ninhd.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj.dtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.vT.Bg.Jy.Lj.Tai lieu Luan vT.Bg.Jy.Lj van Luan an.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an – 76 – I EC TS 60079-32-1 :201 3+AMD1 :201 CSV © I EC 201 H L Walm sley, Electrostatic Prevention 25 (201 2) 263-273 ignition hazards with plastic pipes at petrol stations, J Loss Development of charge in low-conductivity liquids flowing past surfaces: Experimental verification and application of the theory developed for tube flow, I Koszm an an d J G avis, Ch em Eng n g Sci , 7, (1 962) , 023-1 040 K Asan o, Electrostatic potential and field in (1 977) , 277-1 281 a cylindrical tank containing liquid, Proc I EE, 24, L G Bri tton , Avoiding static Ignition Hazards in Chemical Operations, Cen ter for Ch em ical Process Safety of th e Am erican I nstitu te of Chem ical Eng i n eers, N ew York 999 L G Britton, an d H L Walm sley, Static Electricity: New Guidance Rates, Process Safety Progress, 31 N o 3, (Sept 201 2) L G Britton and J A Sm ith, (1 988) , 53-62, 63-78 Static hazards of drum filling, for Storage Tank Loading Pl an t/Operati ons Progress, N o L G Britton an d J A Sm ith, Static ignition hazards of ‘conductive’ liquids during container filling, Process Safety Prog ress, 29 N o (J un e 201 0) , 98-1 02 L G Britton, an d J A Sm ith, 309-328 Static Hazards of the VAST, J Loss Preven tion , 25 (201 2) , L Post, M G l or, G Lü ttg ens and B M aurer, The avoidance of ignition hazards due to electrostatic charges occurring during the spraying of liquids under high pressure J Electrostatics 23 (1 989) , 99-1 09 M G lor, Overview of the occurrence and incendivity of cone discharges with case studies from industrial practice J Loss Prevention (2001 ) 23- 28 M G lor and K Sch wen zfeu er, (2005) 463-468 Direct ignition tests with brush discharges N G ibson and F C Ll oyd, Incendivity of discharges British J Appl i ed Ph ysics (1 965) , 61 9-1 631 J Electrostatics 63 from electrostatically charged plastics Shell Safety Com m ittee: 988 Static Electricity, Technical and Safety Aspects Sh el l I n tern ati on al Petroleu m Maatsch appij B V , Th e Hag ue, th e N eth erl ands, J un e 988 (also avai l abl e as J Electrostatics, 27, parts & 2) T Lan g er, G G ram se, D Möckel, U von Pidol l an d M Beyer, MIE experiments and simultaneous measuring of the transferred charge 3th I ntern ati on al Conference on Electrostatics Apri l 0th to 4th 201 Bang or, Wales 201 J Ph ys : Conf Ser 301 01 2040 Electrostatics requirements for Intermediate Bulk Containers Intended for Use in Explosive Atmospheres J Electrostatics 51 -52 (2001 ) 387-394 U von Pidoll, U von Pi doll , E Brzostek and H -R Froech ten i gt, Determining the incendivity of electrostatic I EEE Trans I ndustry Appl icati ons, 40 (2004) , 467-1 475 discharges without explosive gas mixtures Stt.010.Mssv.BKD002ac.email.ninhd.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj.dtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.vT.Bg.Jy.Lj.Tai lieu Luan vT.Bg.Jy.Lj van Luan an.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an I EC TS 60079-32-1 : 201 3+AMD1 :201 CSV – 77 – © I EC 201 U von Pi doll , Ignitability of spray clouds of organic solvents, solvent/water mixtures and water-based paints by electric sparks and open flames I EEE Trans I n du stry Applications, 44/1 (2008) , 5-1 _ Stt.010.Mssv.BKD002ac.email.ninhd.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj.dtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.vT.Bg.Jy.Lj.Tai lieu Luan vT.Bg.Jy.Lj van Luan an.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an Stt.010.Mssv.BKD002ac.email.ninhd.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj.dtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.vT.Bg.Jy.Lj.Tai lieu Luan vT.Bg.Jy.Lj van Luan an.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an Stt.010.Mssv.BKD002ac.email.ninhd.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj.dtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn C.vT.Bg.Jy.Lj.Tai lieu Luan vT.Bg.Jy.Lj van Luan an.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj Do an.Tai lieu Luan van Luan an Do an.Tai lieu Luan van Luan an Do an Stt.010.Mssv.BKD002ac.email.ninhd.vT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.LjvT.Bg.Jy.Lj.dtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn.Stt.010.Mssv.BKD002ac.email.ninhddtt@edu.gmail.com.vn.bkc19134.hmu.edu.vn