1

Guided By: Mr. D.S. Meena (Deputy Manager EMD) Technical Staff: Mr.RGPatel Prepared by: Pandya AnkitkumarMukeshkumar (Vidhyadeep Institute,Anita!im)

2ACKNOWLEDGENTA summer internship is a g"lden "pp"rtunity #"r a $uddingstudent "# engineering t" e%perien&e #irst hand, the appli&ati"ns"# all the less"ns learnt in &lass. 'his rep"rt em$"dies my gratitude t" the pe"ple (h" ha)e made my stay here a ("nder#ullearning e%perien&e.My sin&ere thanks t" the *R department, "#+'P, !a(as #"r pr")iding me the "pp"rtunity t" pursue my training at +'P,. I e%press my gratitude t" "ur ment"rs Mr. D.S.Meena,Deputy Manager "# the Ele&tri&al Maintenan&e Department #"r ment"ring us and guiding us thr"ugh"ut the &"urse "# "ur training. I am )ery thank#ul t" Mr. R.G.PA'E- and the s(it&hyard team #"r helping us (ith the te&hni&alities "# the plant and its ma."r ele&tri&al &"mp"nents. -astly, I am e%tremely grate#ul t" all the te&hni&al sta## "# +'P,, !a(as #"r their &""perati"n and supp"rt that helped me a l"t during the &"urse "# training. 3Li!t "fC"ntent!Sr n". 'itle Page n"./ Intr"du&ti"n01 2)er)ie( "# Plant34 S(it&hyard50 Generat"r/67 'rans#"rmer//3 'ypes "# 8us$ar system/19 -' : *' S(it&hgear/9; 'ypes "# ,ir&uit 8reaker165 ,urrent 'rans#"rmer(,')19/6 P"tential 'rans#"rmer(P') 46// P"(er -ine ,arrier ,"mmuni&ati"n (P-,,) 414INTRODUCTION: +'P,, the largest p"(er ,"mpany in India, (as setup in/597t"a&&eleratep"(erde)el"pment inthe&"untry.Itisam"ng the ("rld"rld),9gas$asedp"(erstati"ns(0,6/9M>) and 0 p"(er stati"ns in ?"intVentures(/,539.6;M>Gas$ased@0,115M>&"al $ased).Ithas ; rene(a$le Plants als". 'he &"mpanyhas p"(ergenerating #a&ilities in all ma."r regi"ns "# the &"untry. It planst" $e a 97,666 M> &"mpany $y 16/9.5+'P, has g"ne $ey"nd the thermal p"(er generati"n. Ithas di)ersi#ied int" hydr" p"(er, &"al mining, p"(ereAuipment manu#a&turing, "il : gas e%pl"rati"n, p"(er trading: distri$uti"n. +'P, is n"(in the entire p"(er )alue &hainand is p"ised t" $e&"me an Integrated P"(er Ma."r. '"day, +'P, "&&upies the premier p"siti"n in the Indianenergy se&t"r in terms "# siBe and e##i&ien&y. It a&&"unts #"r19C "# Indiaithanin&reasingpresen&einthep"(er )alue&hain,+'P,is(ell "nits(ayt"$e&"minganDIntegratedP"(erMa."r.E India p"(ers Indiaithitse%perien&eande%pertiseinthep"(er se&t"r,+'P, is e%tending &"nsultan&y ser)i&est" )ari"us"rganiBati"ns in the p"(er $usiness. It pr")ides &"nsultan&yin the area "# p"(er plant &"nstru&ti"ns and p"(er generati"nt" &"mpanies in India and a$r"ad.Re&"gniBing its e%&ellent per#"rman&e and )ast p"tential,G")ernment"# the Indiahasidenti#ied+'P,as"ne "#the.e(els "# Pu$li&Se&t"rFMA*ARA'*A+AFa p"tentialgl"$algiant. Inspired $y its gl"ri"us past and )i$rant present, +'P,is(ell "n its (ay t" realiBe its )isi"n "# $eing GA ("rld &lassintegrated p"(er ma."r, p"(ering IndiaFs gr"(th, (ithin&reasing gl"$al presen&eG.>e ha)e )isited +'P,!a(as Gas $ased p"(er stati"n.It is l"&ated near Surat,Gu.rat at$ank "# 'api ri)er. It.6O#E$#%EW O& PLANT: !a(asgas p"(er is &"mp"sed "# t(" &"m$ined&y&lem"dulessupplied$yMHS GE,Alsth"m#ran&e.Ea&h m"dules&"nsists"#t("Gas 'ur$ine Generat"rs/63 m( ea&h, t("(asteheatre&")ery$"ilers(,MI8elAiummake) and"nesteamgenerat"r//3./ M> Page n".3sh"(sthe#igure"#,"m$ined,y&leGas m"dule(hi&h&apa&ityis41;./M>. >e)isited+'P,!a(asGasp"(erstati"n.'heplantisl"&atednearSurat"nthe$ank "#'apiRi)er.It*R8ID"u$le drum n"n#iring assisted ,ir&ulati"n type heat re&")ery $"iler

(9) >*R8 Steam Parameters IPress =l"( 'emperature (kgH&m1) (' 2+H*r)(Deg. ,) *P Steam 9/.4/90716 -P Steam9./ 06 /51(;) Steam 'ur$ine I//3 M>,impulse,tandem(5) ,"ndenserI '(" Pass Sur#a&e ,"ndenser(/6) Generat"r rated "utputI /40 MVA #"r G' : /07 MVA #"r S' Rated 'erminal )"ltage I //.7 !V (ith 8rushless E%&itati"n Rated speed I 4666 RPM'ype "# &""lingI Air,""led (11) 8la&k start #a&ility I 1.7 M> Diesel Generat"r Set9(/1) ,""ling '"(er type I '(" +atural Dra#t ,""ling '"(er (2ne #"r ea&h m"dule)(/4) ,""ling (ater pumpsHI 7 ("ne &"mm"n stand$y)H//5/6mJHhr : Design parameters 11.0 M>, (/0) Pretreatment Plant I 1 ,lari#l"&&ulat"rs ea&h rated #"r /766 mJHhr(/7) DM >ater Plant: '(" streams "# 77 mJHhrSW%TC'(A$D: ="ll"(ing are the main parts "# s(it&hyard in +'P,K1 Main 8usK/ 'rans#er $usK/; 8ays IL 3 Generat"r $aysL ; -ine $ays ( 3 &"mmissi"ned and 1 #uture)L 1 Stati"n trans#"rmer $aysL / 8us &"upler $ayL / 8us trans#er $ay 'here are t(" 116k) main $uses ea&h "# &apa$le "# taking (h"le &apa&ity"#plant (373.1M>).'rans#er $us is n"rmally dead and is used in &ase any "ne "# the$ay is ha)ing#ault. It pr")ides alternate path #"r the #l"( "# p"(er in &ase"# #ault. It &an $e used "nly i# "ne has t" ("rk "n is"lat"r and $reaker "# that $ay.10'he generated p"(er trans#er t" /; di##erent $ays as #"ll(sI(/) !a(as *aldar)aI (7) !a(as DastanI(1) !a(as *aldar)aII(3) !a(as DastanII(4) !a(as Va)I (9) !a(as I&h&hhap"reI(0) !a(as Va)II(;) !a(as I&h&hhap"reIIA $ay &"nsists "#1 ,ir&uit 8reaker, 0 Is"lat"r, / ,urrent 'rans#"rmer, /,apa&iti)e V"ltage 'rans#"rmer, / -ightning Arrest"r, 1 earth s(it&hes.In S(it&hyard thereare#"ll"(ing&"desusedt"Identi#y (hi&h eAuipmentis&"nne&tedI71 Itis saysthat&"nne&ted de)i&e is &ir&uit $reaker.;5It is says that &"nne&ted de)i&e is is"lat"r.6/,61.'he #irst t(" digits indi&ated (hi&h 8ay is ."ined.EMAMP-E 6/71/Imeans $ay/,&ir&uit$reaker/ is &"nne&ted.Generat"r:It is the main eAuipment "# the P"(er stati"n. It takes me&hani&al p"(er thr"ugh the steam : gas tur$ine and &"n)ert it int" Ele&tri&al p"(er generat"r generates //.7 !V.Manu#a&turer I GE, Alsth"m Made in #ran&e,""ling "# stat"r &"reIAir a$s"lute pressure / $ar,""ling "# >inding Stat"r I Indire&t R"t"rI Dire&t Apprant P"(er I /40 MVAP"(er #a&t"r I 6.;11Rated )"ltageI//766 )Rated &urrentI391; A=reAuen&yI76*BSpeedI4666 rpmE%&itati"n I /55 )GT Tran!f"r)er: *++,-.//01Manu#a&turer I =u.i ele&tri& ?apan4 L N ,76 *B, yd//'emperature rise "ilI 76O&Ma%imum am$ient temperature I 76O, *V-VRated p"(er (MVA) I//7//7Rated )"ltage (!V)I 115//.7Rated &urrent (A) I156 7990Impedan&e)"ltage I10 MVA *V side'ap &hanger al(ays "n *' side. In this trans#"rmer there is "##l"ad tap &hanger is used. 8e&ause (e &an )ary the l"ad using Generat"r.12T(PES O& B2S BA$ S(STE %N SW%TC'(A$D:TheainCriteria!T"beC"n!ideredDurin3Selecti"n"f "neParticular Bu! 4 Bar Arran3e)ent Sche)e A)"n3 Other!Simpli&ity "# system.Easy maintenan&e "# eAuipments.MinimiBing the "utage during Maintenan&e.=uture pr")isi"n "# e%tensi"n (ith gr"(th demand.2ptimiBing the sele&ti"n "# $us $ar arrangement s&heme s" that it gi)es ma%imum return #r"m system.'here are #"ll"(ing types "# $us$ar systemI(/) Single $us system(1) D"u$le $us system(4) D"u$le $reaker $us system(0) 2ne and hal# $reak $us system(7) Main and trans#er $us system(3) D"u$le $us system (ith $ypass is"lat"rs(9) Ring $us system*+1 Sin3le bu! !y!te): Single8usSystemissimplestand&heapest"ne.Inthis s&hemeallthe #eeders and trans#"rmer $ay are &"nne&ted "nly single $us.

Ad5anta3e! "f Sin3le Bu! Sy!te)/) 'his is )ery simple in design.131) 'his is )ery &"st e##e&ti)e s&heme.4) 'his is )ery &"n)enient t" "perate. Di!ad5anta3e! "f Sin3le Bu! Sy!te) /)2ne $ut ma."r di##i&ulty "# these type "# arrangement is that, maintenan&e "# eAuipment "# any $ay &ann"t $e p"ssi$le (ith"ut interrupting the #eeder "r trans#"rmer &"nne&ted t" that $ay 1)'he ind""r //!V s(it&h$"ards ha)e Auite "#tensingle $us $ar arrangement.*/1 D"uble bu! !y!te):/) In d"u$le $us $ar system t(" identi&al $us $ars are used in su&h a (ay that any "utg"ing "r in&"ming #eeder &an $e taken #r"m any "# the $us.1) A&tuallye)ery#eederis&"nne&tedt"$"th"#the$usesinparallelthr"ugh indi)idual is"lat"r as sh"(n in the #igure.14

8y &l"sing any "# the is"lat"rs "ne &an put the #eeder t" ass"&iated $us.8"th"# the $uses are energiBed andt"tal#eedersaredi)ided int"t("gr"ups, "ne gr"up is#ed#r"m"ne$usand"ther#r"m"ther$us.8utany #eeder at any time &an $e trans#erred #r"m "ne $us t" "ther. 'hereis"ne$us&"upler $reaker (hi&hsh"uld$ekept&l"seduring$ustrans#er"perati"n.="rtrans#er"perati"n,"nesh"uld #irst&l"sethe$us&"upler&ir&uit$reake rthen&l"setheis"lat"rass"&iated(ith the$us t" (here the #eeder ("uld $e trans#erred and then "pen the is"lat"rass"&iated(iththe$us#r"m(here#eeder istrans#erred.-astlya#terthis trans#er "perati"n he "r she sh"uld "pen the $us &"upler $reaker.Ad5anta3e! "f D"uble Bu! Sy!te)D"u$le 8us 8ar Arrangement in&reases the #le%i$ility "# system.Di!ad5anta3e! "f D"uble Bu! Sy!te)'he arrangement d"es n"t permit $reaker maintenan&e (ith"ut interrupti"n.(4) ain and tran!fer bu! !y!te):15'his is an alternati)e "#d"u$le $us system. 'he main &"n&epti"n "#Mainand'rans#er8usSystemis,heree)ery#eeder lineisdire&tly&"nne&ted thr"ugh an is"lat"r t" a se&"nd $us &alled trans#er $us. 'hesaid is"lat"r in $et(een trans#er $us and #eeder line is generally &alled$ypass is"lat"r. 'he main $us is as usual &"nne&tedt"ea&h#eederthr"ugha$ay&"nsists"#&ir&uit$reakerandass"&iated is"lat"rs at$"thside"#the$reaker.'hereis"ne$us&"upler $ay(hi&h &"uplestrans#er$usandmain$usthr"ugha &ir&uit $reaker andass"&iatedis"lat"rsat$"th sides "# the $reaker. I# ne&essary the trans#er $us &an$e energiBed $y main $us p"(er $y&l"sing thetrans#er$us&"upleris"lat"rs and then $reaker. 'hen the p"(er in trans#er $us &an dire&tly$e #ed t"the#eederline $y &l"sing the $ypass is"lat"r. I# the main&ir&uit $reakerass"&iated (ith #eeder is s(it&hed "## "r is"lated#r"m system, the #eeder &an still $e #ed in this (ay $y trans#erring it t"trans#er $us.

16S6itchin3Operati"nf"rTran!ferrin3a&eedert"Tran!ferBu! fr")ain Bu! 6ith"ut %nterrupti"n "fP"6er(i) =irst &l"se the is"lat"rs at $"th side "# the $us &"upler $reaker.(ii) 'hen &l"se the $ypass is"lat"r "# the #eeder (hi&h is t" $e trans#erred t" trans#er $us.(iii) +"( energiBed the trans#er$us $y &l"sing the $us &"upler&ir&uit $reaker #r"m rem"te.(i)) A#ter $us &"upler $reaker is &l"sed, n"( the p"(er #r"m main$us #l"(s t" the #eeder line thr"ugh itsmain $reaker as(ellas $us &"upler $reaker )ia trans#er $us.()) +"(i#main$reaker"#the#eederiss(it&hed"##,t"talp"(er#l"((ill instantane"usly shi#t t" the $us &"upler$reaker andhen&ethis$reaker (ill ser)ethepurp"se"#pr"te&ti"n #"r the #eeder. Ring Bus System: 'he s&hemati& diagram "# the system is gi)en in the#igure. Itpr")ides a d"u$le #eed t"ea&h#eeder&ir&uit,"pening"ne$reakerundermaintenan&e"r"ther(ised"esn"ta##e&tsupplyt"any#eeder.8utthis systemhast("ma."rdisad)antages.2ne as it is&l"sed&ir&uit systemit isne%t t"imp"ssi$le t"e%tendin#utureandhen&e it is unsuita$le #"r de)el"ping system. Se&"ndly,duringmaintenan&e "r any "ther reas"n i#any"ne"#the &ir&uit$reaker inringl""piss(it&h"#relia$ility"#system$e&"mes)eryp""ras$e&ause&l"sedl""p$e&"mes"pened. Sin&e, at thatm"ment#"ranytripping"#any$reakerinthe"penl""p&ausesinterrupti"ninallthe#eeders $et(een tripped $reaker and "pen end "# the l""p.17 -' A+D *' S>I',*GEARDe#inati"n "# s(it&hgearIA s(it&hgear "r ele&tri&al s(it&hgear is a generi& term (hi&h in&ludes all the s(it&hing de)i&es ass"&iated (ith mainly p"(er system pr"te&ti"n. It als" in&ludes all de)i&es ass"&iated (ith &"ntr"l, metering and regulating "# ele&tri&al p"(er system. Assem$ly "# su&h de)i&es in a l"gi&al manner #"rms a s(it&hgear. 'his is )ery $asi& de#initi"n "# s(it&hgear.18LT !6itch3ear:+ati"nal and internati"nal standards de#ine the manner in (hi&h ele&tri& &ir&uits"# -Vinstallati"ns must$e realiBed, and the&apa$ilities and limitati"ns "#the)ari"us s(it&hing de)i&es (hi&h are &"lle&ti)ely re#erred t" as s(it&hgear.'he main #un&ti"ns "# s(it&hgear areI Ele&tri&al pr"te&ti"n Ele&tri&al is"lati"n "# se&ti"ns "# an installati"n -"&al "r rem"te s(it&hing&uncti"n "f LT !6itch3ear: 'he aim "# is"lati"n is t" separate a &ir&uit apparatus #r"m the remainder "# the system (hi&h is energiBed, in "rder that pers"nnel may &arry "ut ("rk "# the is"lated part is per#e&t sa#ety. 19 iniature Circuit Brea7er -' s(it&hgear is used #"r #"ll"(ing purp"sesI(/)'" Pr"te&ti"n "# the &ir&uits(Against 2)erl"ad,2)er&urrent)(1)'" Pr"te&ti"n "# Pers"n(4)S(it&hing"## #"r me&hani&al maintenan&e ("rk

'T !6itch3ear:A s(it&hgear may $e a simple "penair is"lat"r s(it&h "r it may $e insulated $y s"me "ther su$stan&e. An e##e&ti)e alth"ugh m"re &"stly #"rm "# s(it&hgear is the gas insulated s(it&hgear (GIS), (here the &"ndu&t"rs and &"nta&ts are insulated $y pressuriBed sul#ur he%a#lu"ride gas (S=3). 2ther &"mm"n types are "il "r )a&uum insulated s(it&hgear. 'he &"m$inati"n "# eAuipment (ithin the s(it&hgear en&l"sure all"(s them t" interrupt #ault &urrents "# th"usands "# amps. A &ir&uit $reaker ((ithin a s(it&hgear en&l"sure) is the primary &"mp"nent that interrupts #ault &urrents. 'he Auen&hing "# the ar& (hen the &ir&uit $reaker pulls apart the &"nta&ts "pen (dis&"nne&ts the &ir&uit) reAuires &are#ul design.20Type "f 'T !6itch3ear(/) 8y insulating mediumI Air, 2il, Gas, Va&uum (1) 8y purp"seIIs"lating S(it&h, -"ad $reak s(it&h, Earthing S(it&h (4) 8y V"ltage &lassI-"( )"ltage(less than / kV A,)Medium )"ltage (/ kV A, thr"ugh t" appr"%imately 97 kV A,)*igh )"ltage (97 kV t" a$"ut 146 kV A,)Generally ,ir&uit $reaker are identi#y a&&"rding t" (hi&h ar&Auen&hing medium is used there are #"ll"(ing types "# &ir&uit $reaker.(/) 2il ,ir&uit $reaker(1) Air $last ,ir&uit $reaker(4) Air $reak ,ir&uit $reaker(0) Sul#ur he%a#lu"ride &ir&uit $reaker(7) Va&uum ,ir&uit $reaker21Oil Circuit brea7er

2il &ir&uit $reakers rely up"n )ap"riBati"n "# s"me "# the "il t" $last a .et "# "il al"ng the path "# the ar&. 'he )ap"r released $y the ar&ing &"nsists "# hydr"gen gas.22Air Circuit Brea7er:Air &ir&uit $reakers may use &"mpressed air (pu##) "r the magneti& #"r&e "# the ar& itsel# t" el"ngate the ar&. As the length "# the sustaina$le ar& is dependent "n the a)aila$le )"ltage, the el"ngated ar& (ill e)entually e%haust itsel#. Alternati)ely, the &"nta&ts are rapidly s(ung int" a small sealed &ham$er, the es&aping "# the displa&ed air thus $l"(ing "ut the ar& ,ir&uit $reakers are usually a$le t" terminate all &urrent #l"( )ery Aui&klyI typi&ally $et(een 46 ms and /76 ms depending up"n the age and &"nstru&ti"n "# the de)i&e. DSimply Air is used t" Auen&hing the ar& pr"du&ed $et(een t(" &"nta&ts.E 23Sulfur he8aflu"ride circuit9brea7er: 'hese $reakers are a)aila$le #"r ind""r "r "utd""r appli&ati"ns, the latter $eing in the #"rm "# $reaker p"les h"used in &erami& insulat"rs m"unted "n a stru&ture. ,urrent interrupti"n in a high)"ltage &ir&uit$reaker is "$tained $y separating t(" &"nta&ts in a medium, su&h as sul#ur he%a#lu"ride (S=3), ha)ing e%&ellent diele&tri& and ar&Auen&hing pr"perties. A#ter &"nta&t separati"n, &urrent is &arried thr"ugh an ar& and is interrupted (hen this ar& is &""led $y a gas $last "# su##i&ient intensity.A gas $last applied t" the ar& must $e a$le t" &""l it rapidly s" that gas temperature $et(een the &"nta&ts is redu&ed #r"m 16,666 ! t" less than1666 ! in a #e( hundred mi&r"se&"nds, s" that it is a$le t" (ithstand thetransient re&")ery )"ltage that is applied a&r"ss the &"nta&ts a#ter &urrent interrupti"n. Sul#ur he%a#lu"ride is generally used in present high)"ltage &ir&uit$reakers at rated )"ltage higher than 71 kV.24Characteri!tic! "f S&: circuit brea7er:*+1Simpli&ity "# the interrupting &ham$er (hi&h d"es n"t need an au%iliary $reaking &ham$er.*/1'he p"ssi$ility t" "$tain the highest per#"rman&e, up t" 34 kA,(ith a redu&ed num$er "# interrupting &ham$ers.*;1Sh"rt $reak time "# 1 t" 1.7 &y&les*hen t(" #a&e t" #a&e &"nta&t areas are .ust $eing separatedt" ea&h "ther, they d" n"t $e separated instantly, &"nta&t area "n the &"nta&t #a&e is $eing redu&ed and ultimately &"mes t" a p"int and then they are #inally det"u&hed. Alth"ugh this happens in a #ra&ti"n "# mi&r" se&"nd $ut it is the #a&t.26At this instant "# det"u&hing "# &"nta&ts in a )a&uum, the &urrent thr"ugh the &"nta&ts &"n&entrated "n that last &"nta&t p"int "n the &"nta&t sur#a&e and makes a h"t sp"t. As it is )a&uum, the metal "n the &"nta&t sur#a&e is easily )ap"riBed due t" that h"t sp"t and &reate a &"ndu&ting media #"r ar& path. 'hen the ar& (ill $e initiated and &"ntinued until the ne%t &urrent Ber".At &urrent Ber" this )a&uum ar& is e%tinguished and the &"ndu&ting metal )ap"r is re&"ndensed "n the &"nta&t sur#a&e. At this p"int, the &"nta&ts are already separated hen&e there is n" Auesti"n "# re)ap"riBati"n "# &"nta&t sur#a&e, #"r ne%t &y&le "# &urrent. 'hat means, the ar& &ann"t $e reesta$lished again. In this (ay )a&uum &ir&uit $reaker pre)ents the reesta$lishment "# ar& $y pr"du&ing high diele&tri& strength in the &"nta&t gap a#ter &urrent Ber".$atin3 "f #acuu) circuit brea7erI Manu#a&tured $yIA88 Rated V"ltage I/1 !VRated ,urrent I/176A=reAuen&y I 76 hBS, $reaking ,urrentI 00 !A27Sh"rt &ir&uit &urrent durati"n I 4 se&"ndSh"rt &ir&uit Making &urrent I//6 !A2perating me&hanism I Spring "peratedCurrent tran!f"r)er: A ,urrent trans#"rmer is used #"r measuring alternating &urrent t" gether(ith )"ltage trans#"rmer (P').>hen &urrent is t"" high in the &ir&uit apply dire&tly t" the ,', ,' redu&ed &urrent a&&urately pr"p"rti"nal t" the &urrent in the &ir&uit, (hi&h &an $e &"n)eniently &"nne&ted t" measuring and re&"rding instrument.,' is generally used #"r metering and pr"te&ti"n purp"se in p"(er industries. -ike any "ther trans#"rmer, a ,urrent 'rans#"rmer has a primary (inding, a magneti& &"re, a se&"ndary (inding the alternating &urrent inprimary (inding pr"du&es an alternating magneti& #ield in the &"re, (hi&h then indu&ed an A, &urrent in the se&"ndary (inding in &ir&uit. 28Design of CT:As sh"(n in #igure se&"ndary is &"nne&ted (ith Ammeter and a s(it&h.In healthy &"nditi"n (hen s(it&h is "n means &urrent )alue is same as desired )alue. >hen #ault is "&&urred the s(it&h is "pen Aui&kly the ,' trip suddenly as the )alue "# &urrent is less "r high as per the desired )alues.'he m"st &"mm"n design "# ,' &"nsists "# a length "# (ire (rapped many times ar"und a sili&"n steel ring as ar"und &ir&uit $eing measured 'he ,'