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TOBACCO SCIENCE

CHANGE IN GAS VOLUME DURiNG PUFFINGOF A LIT CIGARETTE 1

..' ' .Y P. SOMASUNDARAN*,

Research Department, R. J. Reynolds Tobacco Co.. Winston-Salem, N.C.. U.S.A.

[.'or t!xamrlc, while Schur arId Itickards (1) reported in1957 that there i!l a sif{nificant volume chango duringpuffing of cigarettes, Mitchell (2) reported in 1962 thatthere is no volume change2 and Newsome and Keith (8)rerx>rterl in 1957 that there i~ NOme volume change whichis about half of that reported by Schur and Rickards. Itis aJKO posKible to deduce the existence of such a volumeclIange from. the reported J(RR comrJOsition of smoke(3-8). For example, the pl"OlJQrtion by volume of nitro-gen in smoke is reported by Keith and Tesh (4) fx} be67.2%. The corresponding valu(' for nitrogen in dry airis 78%. Alisuming that only negligible amounts of nitro-gen are consumed by combustion reactions, this indicatesat least a 16% increa.~ in the total volume due to com-bustion. There has been no attempt heretofore to studyhow this volume change depend Ii on time during a puffor how it varies with experinlenuu procedures.

The purpose of the work reported here waR to ascer-tain whether there iR actually allY volume change andalso to obtain, uRing fast-responding and sensitive in-strument8~ the instantaneous volUme changes during the

t' .INTRODUCTION

A knowledge of the relationship bet".een the volume ofair entering a lit cigarette during puffing and the volumeof smoke produced is helpful in understanding the me-chanism of burning of ciy,arettes. In addition, it is es-sential to have this knowledge to properly conduct smok-ing experimt"nts, f'.8pecially those using "reverse smok-ing," in which a certain amount of air is forced throughthe lit cigarette u!!ing a p.)sitive pre.'Iliure to produce8mokt~ for further study. The volume balance of com-bustion can be used also in analyzing and checking thereported f{as composition of smoke.

The~ have lIeeu two or three a.ttemptB in tht" past todetermine the volume chlmge duriug puffiny" but thel'eporterl rcsults are not in agreement with each other.--- ~-~.

'P.~ """""N at ," TDbot'r" CA_iztr R~'IG1'CA C"'f"'~. Oct.12-21, 19611. j.. P~/,.i.. l'nhylv..-iD.

"D,.. ,\lil"I,..u ... i"~4 0,.. K. J. Jf.~..eIl i. . ~I, ~ft; ,;.,.(Od. 1969) fila' h. hcu - fOtCafl II.., ,"". u . .01.."., elr.lIg~ 4""'1#,.. Ii JIg .

-1"""'41 .".,.., A'.n.-i.', 1"'01""'0.-. Sr..,." of I;',gi"~,,;ng ead Alii'"S."j"" (.".,I";lO!Ii" IJ'lit',r.,'.r, Nt..., }"u,". N.}'. 1/11/21.

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Tran.due.r Indicatorand Record,r

Figure 2--Apparatus for determlninq the e«e~t ot smoke on flow rale~~tral by IImit;ng arifi~e.

pUffill~. Th('sc V'lllume challJ!es were detl'rmined bymeasuJ'inJ! the flow rute of the ~lir enlerin~ the cigarettewhile smoke jR produced at a known conRlant rate. Hydetern1injng the volume change as a function of a tillie,it waR poKsible to ~et. some jnRight into the progress ofburnjng during puffill~.

EXPERIMENTAL

The experimcnts consisted e~~ntially of mechanicalpuffinJ( of a lit cigarette at 16.57 cc!'~ec rate for twoseconds and meusuring the flow rate of air entering thecigarette. The ~lpparatus used (Fig. 1) consists of twomajor parts, one for pllffing and the other for measur-ing Lhe flow rate of incomo1g air.

The part for mechanical puffing consists of a ciga-rette holder connected to a vacuum line through alimiting orifice and solenoid valve operated by a pairof electrical timers. ,!'imer 1 activated timer 2 onceevery minute or when desired. One of the cams oftimer 2 was adjusted to enertlize the solenoid, andth(!reby to upen the valve between the vacuum line andthe limiting orifice, for two seconds. Adjustments ofthe tW() produced the puff for two seconds at desiredtimes.

A (~tm1bridge filter held in a filter holder between thecigarette and the limiting ortfice prevented the deposi-tion of particulate matter in the orifice. The orifice usedin the present experiments maintained a flow rate of16.57 cc./~ec.

Experiments were conducted with 100 mm cigarettesburning between 1 and 4 cm from the front. The ciga-rettc waR f'nclo.~ within a tllass jacket fittillg a tlroundtllass joint on the cigarette holder. The air flow into thejacket wus determined by measuring the pressure dropaC1"QS8 a 2.6 cm lonK regular cigarette filter". At theflow rates used, the pressure drop was le~s than 8 cmH:!O. Thi~ is less thnn 1 ~f, of atmospheric pressure(10:~3.2 cm) NO that the expanRioll of Lhe entering airin pasRillg through thc flow meter ('an be nej{lected.

A :!~1. p~i pres~ure trtln~duc('r with a natlll.cll fre-quellcy of about. 2000 cps under our conditions wa.~ uNedto n1t'nNI1re the pressure drup. Its negative probe wa..~introduced b('tween the cij{clrette filter and the jacketand the positive probe WtlH exI>osed to the atmospher(!.

Any flow through the flow meter produces a correspond-ing electrical signal from the transducer. This AC signalis demodulated by .l transducer demodulator and theoutPllt from the ulller is f{'d into a strip chart recorderand an OSCillORCOPf! fitled with a cnmera. The oscilloscopeand the camerll shuttcl' were both triggered a fractionof .l Rl.'Cond bef(.rl~ the be,l!illninj{ of a puff by timer 2.The arran~ement placed Ule beginnin,l! of the puff at theRanle point on all photol!rllphH of the oscilloscope traces.The oscilloscope defleclion was directly proportional tothe flow rate of air.

With an unlit ci~arett~ in the holder, the flow rateillto :the glusR jacket ill essentially the same as the flowrcltp of gages exiling from the cigarette. Hence, infor-mation on volume change due to burning can be obtainedby compclrinJ! oscillol{COl1e tracell obtained with the litand unlit cigarettes, Vo1umes were obtained as integralsof flow rates by w~ighing xerox copies of the relevantsections. Weighing of seven different xerox copies of aparticular area gave a mean reading of 0.2618 :t: 0.0045.I-'or calculating the volume change during combustion,the ratio between the areas of two regions was used.The standard deviation for a volume change of 14.7%for a particular test, as obtained from 8 different meas-urements (xeroxing and wei~bing) of a single phot&graph was found to b~ 0.4%. For larger volume changesthe standard deviation is a smaller percentage of thevolume change than that in the above case,

Smoke filtrate has somewhat different physical prop-erties than air and the flow through a limitinv; orificemay be affected by these. This problem was studied withthe help of the experimental set up shown schematicallyin Fig. 2. The part for producing the standard puff isthe same as that described earlier. The flow ratethrough the system was measured by means of a pres-sure transducer, a soap bubble meter, and a rotameterwith lit and unlit cigarettes in the holder. On1y oneof these three instruments was used during any par-ticular experiment. Their positions are shown in Fig.2. With the unlit cigarette in the holder, air flowsthrough the system, including the limiting orifice,whereas with the lit cigarette in the holder, smokeflows through it. As mentioned in footnote 3, a regularcigarette filter cannot be used as a flow meter whenit is to be between the cigarette and the limiting ori-fice. A glass tube (3 mm dia x 4.4 cm length) wasused as the resistance element in this case. The lengthof the tube has to be limited to keep the dead volumelow, with the result thclt the prt~sure drop is signifi-cantly less than that obtaine« with the filter. There-fore. a more sensitive :to.1 psi tl'.Lnsdllcer was usedin this experiment. The Hp:\n (If the indicator wasadjusted to 2.5 cm of "'ILler fullll\:all'.. During preliminury c.xpcriln~lltK.. it was ob~ervedth~Lt the time int.crvn I hct\VCl!11 lhe ellclosing of a litcigclrette with the jarket all(1 UI'~ beginning of the puffis un import.Llll p;lr:IIII('ter illllucneing the volume('hnngc «llrillg plillillv;. Tlli~ lime illterval was con-trolled and measure« by noting tile distance betweenthe strip chart reeorclillg~ of preSHure changes due tothese event~. DuJ'in,l! the alJove t.ime interval, the glowcone is essentially b~ing choked as there is no sllpplyof additional oxygen to the glow cone. This time periodis therefore called in thiH p:Lper "choking duration."

Becau/le R sensitive und lluickly responding trans-rlucer-dcmodulator-osl~illosrope combination wc~s used,it WUH p(IH~ible tl. r~cord HmiL11 and rapid changes inthe flow ri~te8 of the enterillg air as a function of timeduring the two-second puffs. The jacket used wassllfficiently small to hnve only an insignificant effecton the sensitivity of the flow rate measured. On theother hand, any expanKion of air inside the jacket dueto heat from the glow cone and the amount of side-

8Th" ..,Irrlj"n of Ih" ,."sina""" ,lfflle", of .. ~Oft' fI",I.". dl'!' d. 0.. Ill,t/,""'" of Ihl' ..ri'.".ill"'" 10 bc /","fo,.med. I" Ih" pr"..."" rose. 0 !'r'f.f"'..drOl/, i.. th.. P".., m..'"r o( mqr" Iha.. 1% of al"""f;hrrit: £ "'SSlfr~ is 01...i,lrd

Ie." Ih~ ",'.f ","i,!'r".f.ihihly "g..(ls d,,~ 10 Ih" /"."s..".,.." Ih" J/p,.. IlIc/~r "..

sig.ifi,"'HI. Th, lias flow Ih,oUllh Ih" ,e.is/nu"..., .fh"" d "" la",iu"r, rhiff"..ilil"I,.s Ji,..,'1 ",'o1ualio" of Ihc ~'.." rul.. f',"" Ih.. ",r/,..ri""",lal ,1"la forpr...sur,' ",.../'. I','r air 1/, of a"'"" IA,.il ...'I.f,,( th.. /"..s.ur.. d",/, i" "lu/l.. of a/,/"",/,ri.,'" .Jionl/,l,.. f"r I"",i"a, fl,..(' a"d .if as,'u,,N.' "'""Ih. (.t/,0 c",. i,f k,s Ih"" 0.1% of Ih.. al"ws/,h..,;c /,,"f,ffi'/', I"',','if~ "','a,f',r,'",.',,1..f s"rh s",nll /,"'SSlf'" d..o!". rcq"i s d~I..'ul" u"jus/""", '" cli'"i""I" ",.i""Jo,.""/"",., I.. "".. oth .ftlldi air jl"", Ihroullh "cv"lar r;I/""""c jillcrs hu.t~'" ,...;cri""",tall)' conjinlle,t 10 b, lI,milf4r. IVh"" a prC,f""'C dr.,/, ,,; Z 1oS "III 11,<1 ca" b" tol"rut"". .. """-1' of ,"ill"""'" /III,.. "U". Ih"'l'fo,e. b.-"""r/'""","v ".f..,t n. th, "".fislat""', 11'1 Ihc p..." fIIl't"r is ", b" /,Ia.-"dhrl1""". I",' ht cipnr,,"" n"J Ih.. litHili.p orifir~. u fillcr ","",," /:( .I.f,,"""'-UU,f~ d/',..,..il;on f,.o", _ok.. or ..ve" .1.. wi'"" f'hsse _,dd "ha..pc llac

,ifl,,",'" of Ih.. ,lillrr ','"..rd. ga,f flonr, IN .IN,h a CIA"'. a gIU,f" lube 0" ...,,/01, I,d... of Ill.. Sl=.. d,scrib.,d «I'm', i. ",rd,

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~TIM£Fiqw. 3a & b-'r.sswr. drap v.rsus t;m. t... ~.co!td p"t with 101.nlit and Ibl lit c(9ar.tt.. In the ciqor.tte holder ond t:o.sducerprobes b.tweea cl90r.tte oad IiMitlR9 orllce. X-o." 1 dlvltl..=O.28StK.: ,-aals 1 dlwkloa-,3.0' cc/tec. at ot ~erIc pressure.

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stream that might re-enter the cigarette during puffingis increa.'led by the use of a I!maJler jacket.

RESULTS AND DISCUSSIONEffect. of .\'Inllkr (In J.'[(lI(' R(III' Contr(ll bll the Linlit.-

ing Orificl'. Mea~uremelltN to determine the t!ffc<:t ofsmoke on flo\V rate l'ontrul by 11 ]imiting orificl! IlllVl' th('f(illowillg rt'ltults:

(a) Tc~t.H with l>ul)ble m(;lt'r--l)at~1 obtllillt,ti \\.iththi:c tt hnique wa~ IIC(:.urate ollly within 2'.;.. With 1111unlit cigaretw in the holrl('r and, therefore, air fll,\\rilllCthrouJ{h the lIystem, the v()lume \\'I\.'I found ~ be 32.6.With a lit ciJ{:\1'I~tte ill the holder alld, therefore, KD1okettowinlt through tile Hyskm, it Wlt8 :12.7. It C;\Il be !\{'('IIthat Hmoke hUM lro effect 011 the flo\\. rllte control by thelimiting orifi<:e within the eXlterim('lltal error of thisn1ethod.

(b) 'rests with rotameter for gas flow-The rotame-ter gave a reading of 20.3 :f::0.04. The correspondinllreading for Rmoke was 20.0 :f::O.05. The diffel-ence couldbe due to either an actual decrea.'Ie in the flow rate ora decrense in the density of the Kas medium. The non-particulate portion of the smoke contains, however, morecarbon dioxide and less oxygen and nitroJ{en than ispresent in air anti, therefore, haM a higher density.These te.qt.~ Clln therefore be taken to illdicate a reduc-tion in flow rate whell Ute lta!4 flowing through theRystem iR smoke illsteltd of air. The percentage reduc-tion is o'iomewhat more than 1.5~.h.

(c) Te~t.'1 with the tranMducer-The flow rate waafound to be appl'oximateJy 2f:{. Jess \vith the smoke flow-ing through the systen1 instead of air. Two typicaltA'lCiJloseope tra('.e~ obtained for thp air and smoke flowar~ tlhown in FiKs. 38 and 3b, respectively.

The above results indicate that there is a minoreffect between 4';:' (bubble method) and 1.5~~ (rotame-tt~r) of IIm(lke un ftow rate contr()l by limiting orifice.It is po~sible that the bubble meter technique did notshow such an effect because of the larger experimentalerror allllociated with it. Also, since a transducer setwas used for determining the volume change duringpuffing, a 2';';' correction which seemed a reasonableestimate was therefore applied.

Volum.e Change due to B11ming. A typica] trace forthe air flow into an unlit cigarette is shown in Fig. 4.The dashed line represents approximately the corre-sponding curve thnt would be obtained if the gas flow-ing ,vere smoke instead of air. It is with this dashedline that comparisons of traces obtained \vith ]it ciga-rettes are norma]ly made. An example of the trl\Ceobtained with a lit ciJ{arette in the ho]der and withnegligib]e choking of the glow cone is shown in "'iR'.5. For the purp°!le of comparison, the dashed line of"'ig. 4 is sliperimpoMed on }'iK. 5. It can be seen thlttfor the first one-fifth or 110 of a second, the flow ruleof air entering the cigarette is higher than thllt ofthe smoke exiting from the cigarette (stage 1), andin the remaining time of the two-second puff (stage2) it is lo,ver than that of the smoke. It can a]so beseen that there is a J{as flow from the chamber to theoutside for about one-third of a second after thecompletion of the puff (stage 3). The instantaneo\lsvolume change due to burning (the difference betweenbe solid line and the da8hed line) in terms of per-entage of the puffing rate is given in Fig. 6 as a

function of time.The above re8ults show that in the beginning of the

puff the vo]ume of gas consumed by the burning ofthe cigarette i8 ]arger than that prodllced by theburning. Then, as the burning proceeds, more is pro-duced than consumed. The observed change in flowrate during the puff is in qualitative agreement with

<- TIME

fi9... 4-ProfiI. .f air .."r... a. u.lit ci9ar.tt. dllrift9 a twa-SKo.dpu.. Dotted II". I.dicatn ... appro.imat. profil. "at would hay.~ o~tal.ed If was .sn lestrod of air. X.axls 1 dlvlsi..=G.DS MC.; y-oxis 1 dlvlsiM=4.1J cc;wc. at a"'ospHric pr-~.

tile rctlutl~ of Jarrcll and de 1:\ I:urde (6) which in-dicatc lh:lt the oxygen ('Olltlunl(!d by the burning re-actions mcrel,seR alJ the burning pro('ceds with a si-multaneous increase in the carbun monoxide and car-bon dioxide content of the smokc. The increase of wl-urne change in the beginning of puffing is consideredat prcllent to be ILt lea.."t partly due to a change inburnillg characteristics.

Temperature changes within the jat:ket will cause

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Fivure S-Proiil. of olr eIIterin9 a lit ci9arette durin" a two.secondpuW with little choki"9 ot 'Jlow c_. Chokln9 durotionc=: 1.7 sec. Th..dotted line repr...n" the flow rote ot smoke _xitl"9 from t_e ci9arett..X-axis 1 divisio.,,~.O.28S sc.; y.axis 1 divl.lon",,4.13 cc/sec. at atmos.pheric pressure.

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p.'oduced extinction of the glow cone. The above re-sults are plotted in Figs. 7 and 8.

During .the two-second puff and with negligiblechoking, the mean volume change is 28 :!:4% of theair entering the cigarette, Since the wrapping paperis porous, only a part of the air that entered the ciga-rette has actually gone through the glow cone and,therefore, the volume increase due to burning is morethan 28% of the air that has corne in contact withthe glow cone, The total mean volume change duringthe puffing and the immediately following stage 8 is29 :!:4% of the air entering the cigarette.

As mentioned earlier, the reported composition ofcigarette smoke indicates an increase in volume dueto burning and this is in qualitative agreement withthe present results. If no nitrogen has been consumedor produced by the burning, the 28 :!:4'}~ increase involume should correspond to a nitrogen content of68.4 :!:2% (by volume) in the smoke leaving the ciga-rette. The above value is somewhat lower than thevalue (67%) reported by Keith and Tesh for the nitro-gen content in smoke. It is al~o lower than the 78-75% by volume observed from the data of Makhnachev(9) and the 66f{';' from the data of Phillippe (5). Thesehigher values obtained by direct analysis of smokecould be partly due to 1JYOc:11Il:tio)J, if any, of nitrogenduring burning and P;lrl.ly tluc t~) !Ii/fusion of nitrogen

Rome flow of air through the fio~' meter and thu~ simu-late volume Chlttlges due to puffing. (It is sufficient toraise the temlJerature uf about 5 cc of the air inside the.jacket-25ftl of its vulume-thrQugh 1000 to obtainthe increase in volume observed during stage 3.) Inparticular, a heating of the still air at the end of thepuff could ~uuse an uuttlow ilS ubsel-ved during stage:{, and couling by infiu\v of cold air could give rise tothe increased inflow observed in stage 1. However,observatiun of the outnuw recorded immediately afterclosing uf the jacket at the beginning of each experi-ment indicates that the actual volume change due toheatinl,t of the air in the jacket is small compared tothe ob~ervl!d .'ffl'CtS. Presllmahly, the cooling effect ofthe jacket. ~'all predominate::.

}>reJiminary experiments sho,ved that there were nonoticeable differences between puffs in which the po-sition of the glow cone varied between 1 and 4 cmfrom the front end. This was also an experimentallyconvenient range and was used in all experiments.

Volume changes during the different stages of puff-ing of a lit cigarette are given in Table 1. The chokingdurations are also given in Table 1.

The first nine tests are those that were done withthe least experimentally possible choking durations.In tests 10-21, choking duration was purposely vm'ied.Choking for durations longer than that reported often

Vo!. Chanqe I.~taqe I

cc As % otPuft Val.

Table 1. Volume change by colnbustion at various slages

Vol. Challqe i. Total Vol..me Chan'Je In Vol Chon""Stage II Staves I & II ~t,,~.J(' III

ee As % of ee As ':'0 of As % of ,,(: ,,:.P.ft Vol. P..ft Vol. Air rilEi ~

EnteringClqorette

10.022.623518.722215618.511.520.'22.133.99.9

15'-20

0.73.32.'0.00.107

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u..No.

t234S61.,10II121314IS1611II".21

ChokingTim.

10

1.7

26

26

303.9

39

3.';

44

6.5

9.0

10.4

110

182

19.5

21.0234

'47

26.044.0

62.5

-.22-.32-.58-.71-.M-.71-.'7

-."-.n-.51-.1]-.79-.54-.71-.60-.5]-.2'-.17-.44-.046-.10

-0.-I.-I.-2-Z-2-Z'-~-Z-I-0-2-I-Z-I-I-0-0-I-t-0

5.7,.),..1.0,..7.4U5.1'.66.48.43.75.00.10.91.61.10.20.50.]0.0

11.419.420.824.520.822.511.111.120.219.12S.111.415.40.22.64.8340.51.40.80.0

5.55.'627.36.06.15.16.16.7598.32'4.5

-060.31.10.80.00.10.3

-0.1

16.7'841'.022.3'8.228.4IS.'IS.'17.3'81253'.0

IJ.7-2.0

0.7322.5000.10.7

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1.t.~.A2,0..,.I,'1.7..81.71..5J.71.81.70.70.41.00.&0.20.40.00.2

6.25.~'"S.OSJS.I4.'S.IS.6SI~.O1.13.1190.'1.40.00.'

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smaller than the one used here (2 cm dia x 6.3 cmlength), because the amount of oxygen available fornormal smoldering of the cigL\rette depends upon thevolume of the jacket. Experiment-'! with a larg.er jacketconfirmed this expectation. A significant increase jnthe size of the jtu:ket incr~aMes, however, the deadvolume between the probes and the solenoid valve andreduces the sensjtivity of the method. An examjnatjonof the djagram of the jacket used by Mjtchell (2)suggests that significant choking of the glow conemjght have occurred in his sYHtem. This could be thereason for his observation in 1962 that the volumechange due to b\lrning was zero.

SUMMARYA knowledge of the change of gas volume during

pullillg is important for the analysis of the burningprocess of cigarettes and is required in the correla-tion of reverse smoking experiments (in which a posi-tive pre8sure i8 used to force air through a cigarette)with conventional ones in which 8moke ill sucked fromit. A sen8itive and rapidly responding pressure trans-ducer-oscilloscope combinatiuQ was used to meafturethe rate I,t \vhich air was entering the cigarette whilesmoke was sucked for two HOt'tlnd!l at :\ (~onstnnt rate

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into the smoke through the wrapping paper (10, 11).In this (.onllectiun with the Conner poRRibility, it mightbe noted that Jarrell and de la Burde (6) found nonitrol!l'1l ill lh~ nUlmRtream smoke I)f cigaret.tes burnedill a nitrogen-free atmoliphere, inCJiclltinj{ that nitrogenis not. pr()(lut.-erl by the pyrolYl\is relictiollR.

The nitrugen to argun ratio evaluated from the dataof Laurenl', Young and Greene (8) ili 77-84 for smokeand 88 fur air. AsRuming thllt arglm iR neither con-!umed or produced, this indicate!! that some of thenitrogen of the air is consumed during burning. Onthe other hand, it i8 also possible that the above dif-ference in nitrogen t<1 argon ratio is due to experi-mental errclr. The nitrogen to argon ratio that couldlie oIJtnine<l from the dllta of Keith and Tesh is '84for smoke which can be compared with a value of 83.6given for air in the literature (12).

The scattering of values for the volume change, forchoking times of leRs than five seconds, might be dueto a variation in cigarette properties-such as tobaccopacking and wrapping paper porosity-that governthe burning of the (~igarctte. Any variation in volumechange due to a variation in cigarette butt length orpuff number might also tontribute to the scatter. Theamount of air that leaks through the wrapping paperdccrease8 as tlae butt length decreaseH and, therefore,the amount of air that goes through the glow conemay increase Aignilicantly when the burning regionis nearer to the mouth tip.

With regard to the reverse Rmoking technique, theabovo results Khow that <lIte to the variation in chnllsrein flow rntc during II puff as well as due to consider-'Ihle difference8 in behavior between individual ciga-ret.tes, it will be very difficult to control the air inputinto the cigarette so as to get a constant or predeter-mined puff flow rate or even a predetermined totalflmote volume.

It can be seen from Figs. 7 and 8 that the volumechange due to burning decreuseR significantly jf the-low cone is choked. A typical oscilloscope tracingotained during pulling of a lit cigarette after Rome

amount of choking is given ill FiJt. 9 and may be com-pared with that of Fig. G obtained with no chokinv..In the present experimental set up the effect of chok-Ingin'l; could be Dllticed if the choking duratil)n ,vcremure than about [, Meconds. This time interval wouldbc 1:lrger or smlliler than the one reported here if thej.\l.k~t uscd for enclosing the cigarette is larger or

~- TIMERq.re ,-ProAl. of air ..terl... a Ut clqareH. d8rl.,. a two MCo.d"* wi"' so... c~"I~ of t~o 910w co... Chokl-v l.tervalc=1'.1 see."X-axis 1 divlslo.==O.285 ..c.: y-axis 1 dlvlsl...",,4.13 ce/..c. at a""os-pherlc pr~ss_..

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of 16.57 cc/~. The volume challge WR8 .ill iIlCreli~~

I\ycraging 23';;' of the volume of entering ail'. Duringthe fil.st fra(~til," of a second. there was a sm.,ll cle-crease in the volume change followed by a st~ady in-crease. After completion Ilf a lwo-secclnrl puff, thl!ciglirelte continued W prllduce gages for ~I"oul linethird Ilf II IICCOlld, nlakil1J{ the tot.'\1 volume ch~~ngcabout. 29~;. If the Rupply or air to the glll\v \:ol'e jl(reduced prior W lhe puff. the volume inl:rCIIHU i~ re-duced. I.iterHtllre rcpllrt.s that the volum~ chl'"~e illzero miRht he rluc tu Nuch chokillg IIf the c:iRarettc fora few 8~condK prior to the puff.

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~~

ACKNOWLEDGEMENT

The author willhes to thank Dr. K. ./. M;"lIulg forseveral enlightening discussions during the c()urse ufthi~ work,

~

lITERATURE CITED

1. S('hur, M. O. and J. C. Rickarll, ])eperulence RIIIl (}p"'ru-tiof1 of a Multiple Ciltt'I't}tte SmokinJ{ Machine Toba«o &i.I, J:i-2fl, J957.

2. Mitchell, It, I., Controlled ~lt'u~urCIII,!nt of SIII,)kc-Parti"lt, Rt,tRlltion in the RCIIpiloutury Tract. Anh Rev.Rt'1I1IiTt/t. ]li...e//Ht"1C 115, 526-~. 1PI;2.

3. Newsome, J. R. and C. H. K('ith, Quantitative Rtudies,m (~igal'ette Slllllk,'. II. 1'11e ~;frf'(,t of Physical Variables unthe WeiJtht ,If HIIlOkl'. Tobac:eo ""'l'i. J, n8-6:1. 1957.

4, Kpith, (~. .II. ~md I'. G. "p::h, Mea!;ul'ement of TutalSn\okc JIIMuing from a llul-ninf{ l~igurl,ttc, Ttlbacco Sei. 9,I;J -M. 1 !1f.r"

!i. ('hillilll)C, It. J., "Cigarette Smoke Compusition," in:The Kncy"t"1'f'dil. /If ClwmiRt11" 2rul ";d., Clark, G. L, arul(i. G. Hawley, I!;ds., Reinhold Publishing COl'p., N,Y., 1966,PI', 246--19,

6. Jurl'"II, J. E. and de la Burtle, A Stully of the MajorGaMellus CnnstitUI'.1ltR in the Mainstr~am Smoke of a Cigu-rett(!, TobAcco ~. 9, 5-11. 1965.

7, Osoorne, J. S., S. Adam,'k anti M. .~, HnbllB, SoniCColII!,'tnentll "f (~l1g Phase of Cijtarettc SlIIoke, AII,/I. Chelll...ftl, 211-215. 19541-

8. Laurene, A. "., G. W. YounJt and G. H. Greene, un-puhli~hecl work l\t the R. J, ReY.11olds Re~ar"h Lab"ratory.

9. Makhnachf'v, I. <.;., et al, Components of Tobac<.'OSmoke. The Chrmieal Constituents of the Gas-Vapor Phase.IJcit,.. 7'ahakf"rllch. 1, (No.3) 90-12:{, 1968.

10. Newsome, J. R. anI' (~. II. Keith, Vaaiations of theGns I'hupe Composition within a llul'ning Cigarette, TobaccoSei. 9, f05-69. 1005

11. Owen, W. C. anll M. L. Reynolds, The Diffusion ofl;nses thl"OUgh Ci11:arettAJ J'IlIwr During Smoking, Tobacco~i. 11, 14-20. 1967.

12. Weast, R.. C. and .'). M. Selby, EcI8., Handbook 01C/lcm;stry and PhY.'IicR, 'fhe Chemical Rubber Co., Cleve-land, Ohio, 1967, p. F-142.

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