BSTJ 30: 4. October 1951: Heat Dissipation at the Electrodes of a Short Electric Arc. (Germer, L.H.)

5.8 MB·English

‘Heat Dissipation at the Electrodes of a Short Electric Are

Sete ciara ent ne etek
SAR Raut er abide eh
Sr Pike atuticiee amen aia
ESS Seats At er aasaled tem
elt Sc a dC aa

HIS paper is an acouct of diet calormates measurements of the
very tsipated al positive and seyative decLusen whew Ligy are

brought togetier to scharge a bande, Te sxperimer e rales
by the fsct eat che exeion atthe eloure of elect ovatets i due bo
sing anl uncertain Ie the enn a elaine ans ested
Tetwen she ehectodes i hey to hein slveoning © comprehensive
Theory of this ee hich in see may a in tae conzol af contact ersion.

"The expeinents) read s an alaptatin to che present pase ol
proces sot euler in which essed wizes ane eeperated. slough
Together 60 ‘ines pew seta hy mars of e megertielondegenkee nity
tach closere chchanging a onemer ‘hich eraharsed ater the ee
Tne bees separated, For Se presnteapersmenl be le wire ane made
latino ana ave rater heavy, an Cie Bow of Laat rt of hn
Freasurel ly yuis af thenanenyies, These is kr lent of
Tetween the i thermacouple of each jie which ave connected in sree
Us apps each oer tha &yalvimemele i eller wil glee
election pgrional to the tierce fn tsperature armen the wie?
‘Tho low of hea sons cach wie is ealewsted Trou this eayperstare it
ference ard the thermal conductivity and dimensions af the wi. After
raking sme corrections this iv the amount of energy eespated pom
the electrode at cach dcharge of the condenser.

‘The twi plainue Uist wtes have dinners of 0658 com an ec ix
about 2.2m len Fo ised te in sche lap in wey

YL I, Geer JF apt, Pls 2, 95 (ss

fps td cca, App, paca, i 0,

ti etrinon et oman cote Pei 9 oe ane,
OBL Tur ry svstE SEEUSLEAL JOCHSAS, OOTORRR OSL

heowy eer black. The therzeseupes are Chronel Aluel wires of 0012
Cm camer asl me supe ofeach pai sel! tis platinn wte 20
{in ftom the point where the wits lamps in ils copper Block; the ocher
Couple of the pie eleetzcayneuhtd iy x ylas cating and is buried
Snler be athe Block. Te electriesleantact made betwen points of
the latina wes a tle Boyar the welded thermocouple, and opeaing
‘td eeog of the cnet i achive ly atrikiag one of the patina wires
Tyan the point of electrical comact with Ui ingulated armature of
ker wit vibrating a cyl, Rach heavy caper block with its pat
um wite fs mounted op» cantiewer h, the end of which can be move
Ty w aiew to permit ne sect nf the contacts, Adjustment ea be
Inte ako by vacying the volage supplied ta the speaker ui

Tn orcer to minionee Urn disturbances thi epmen mounted
fon a herwy ster lave, and he speaker uni, which éssipates about OL
Iratt during operation, e thermally sine from the contacts by three
CSrveniie hese aluminum coves each i very good thermel contact
Irth the ts! base lL of thie equipment is covered by a silyered bal jar
(OF 21co inside dimers, Nn olominee covered Celoes housing surouade
the bell Jar and she thermocouple qabeimeer, exept far «sual glass
‘winlew for wading the gaovtcometer. Te palvasczcter Ight cured
‘r for onl ut on seed atte tne each Yeading, The experiments
fe cade 2a conse Ieee

‘Albu te sgnicant rete cont fo snaasuromotts ofthe het Al slong
the plainurs wissen seg cre Bevugat togetter (0) Gime pee second
Siscarging st rat cae a cagecity 0 10 exage fo penal of
Sols At his yw a ae oevtrshetceen clean plstnum electrodes if
The vinci inductance eles than om Hat dere i 6 are if the
indetavo snus highes tau this! Hf the wero ave oporeted in the
preerceof wy aso ato nga vapr ey become costed ith c=
Fromacans atrial and arcing then otrame nt rsery eure even when the
Infuctae suite igh. Meesirements ave hn cari oat under three
lieseal eapeaineutal coretions: (1) clean electrode witha cet inde
{ance of 0.08 10 "hrc nar a ery cane, (2) ean electra ths
‘Greitaductance of 193 10-"h nad arcing, cod () electrodes aight
Ceubonved hy limonene vepar mith «ie inductance of 10 > 10-*
Hand av areal every claves, The condition of areingon every lure oF af
Complete sence al arcing, was radi determined for each experiment
by contnnnas msiluccie cbecrvation® The potential uf 40 volts was
chosen a th highist at which thee ie never secon are (in the reverse

50 el Hig
maT pISmAZION AP EIECRODES OF SHOBT BLECTHIC ANC 985

ict) which would impossibly complicate atespetation of the data,
UExparinenta under conditions $ ware cei out with the Limonene vapor
pressure maincsined at shout the lovest value st which sciveton xn be
resuced (0.06 mm Hg in ast experiments). AC tis lar presen iva-
fion doesnot cevelop uml fe letrodes have been operating or sometime,
Tht hen it evel the agen cect poten after an ace eS volta

I

toatl en Sh tel espadie aol whee egies Wser va
[Mpc ere anus by i Te ernest ps onl fs oe
ESSERE MB,

shih als the vale eal after arcing ia the inactive condition. The
hsereance ofthis pen crcl vollaye i raul that each ae isa ae in
Platine, and not eatbon.

Aw sample af data taken upon active ‘carbone electrodes with «
Grail inductance of 10 10- (conditions 3}, aa au ate aLevery closure
fungi an open ccut potensal of ~5 wos as veces by contios
Ciseretion of the oscil scape recaing te potential across the combats,
936 mmr out svete reuunseas jones, ocrones 195t

i given in Fig 1, "Theories ate readings ofthe gulvasomster win it
‘atin ectice With the sheaocouplos in she moving cobtact. The cut for
‘hevging te condense 40 vlts rie tn wt laure eas trad opal
Iminuces wh the petal of the moving contact postive, The potential
tena severed st intcrvls of 1 ives al Sal turned of a 13 rina
{The deletions of 489 and $5.1 mo vecasiond by the enerey disipstad
atthe contact by the Gacange of the condenser respectively when the
Contact was negative end wher wt postive are tonsa ino tempers
fre diferenee ofa ~ Q4213 and AT = O1S2S by multiplying by ar
here w= 3.84 10 anp/mm of the galvanomcter detection, ¢ = 33.7
‘hme cea estanee, ni = 2-41 X JO°C/olt themacouple emsitv>
ity: Neglectg forthe moment sral caretins due to radiation and com-
‘ion Ines these ferperatune erence are converted Isto ost 20%
long the wie of 22s) 284 ete per clove hy mllipling them by che
factor B— 164.5 chain om tae dimensions of the ze, the ternal con
tlesiviy of platinum 0.690 werefemC, and the factor 6D representing
the tombe al disares per sscord

“The eat fn oe othe wes clifers Fra the het dissipated by she
erce upon thal nite Lasso of raason and convectie lores wl base
the sigher temperate ofthe peitve electrode resls in some conduc
tion of heat ta tie uegaive letra at this postofcontct It has been
fond expeiet frst fo ohana wach ere ntende io be fe aa the
Testo these tee tones erve and thee. to carrett fr ration and con
‘reton lees ne ebony eskulaton

"Toe cacy in tne eecltode wie corresponding co the average exces
enpertare ofthe nv above ta enero (07°C) repreeets the
pal cacray of eboa S00 an aus the large seal texperatere ds
tion in one sve appeebly ebange arg the tie the wes are in
uta after arya the tans feat fr net the ater cae
oeced forhy riking usacurements of AT across enc wir for lilernt
Fractions of each eyle ding whi the wires ae in contact and extn
polling the values so dbtned to Ed AT, for aero time of eoalact. Data
Of inst far eapescentl conditions iste e (1) hove are plotted a the
(ome ett ie of Fig, 2a or nitions (3) x the ler tight side af the
fig the 7, wales from Fee cutee aro writen down! on the Ost ne
ff Tae 1-On the upper all of the Sige Ss pots Ue eal best Bowing
Slag Bo mice ests hy multiplying AT ly the lctor B= 1843,
(rt worecting for ration a convection loses).

"AV the old cices om Fig 2 (and Fig 3 who) represent measurements
spor the moving vivir, sad Ee open circle neasuremco's upon the
Stationary elite, Dieceaes boteren the slid icles and the open
TMEAr UISHPATION AT REKGTROWN fr gnu LoReTHBE AR 837
erica. JOURNAL, oerosEK 1951
cay msuaris st aLventoues OF suoRE TereTaRE Ane 999

dels ate be atebate to dienes Ueto the elses, probly
fi tae elective aiean duster, Lox abscredtinge iy Uvearive sllion
iw vices nf i. 2 one ney higher than the ane eieles, Bat
lhe ela or mescrements upon iaetvecuneces, Ths reverse
ol sgnican; we brow about hy ae oxide mich necessitated
rktirg lve taermnvungie to the mosing clocitode site the measure
‘nents rpor the setivecurces kad beeacomplesed and efor the mente
seats upon she Snasive eufces cai puclininay tcl eve we
‘tere of thi ar one mst conslade taat te mel opetstion eed
the roving ehetrede ‘ln the coge ofthe pls at the iat of Fig 3 below
‘meal he data were taker before the revelling operation end sora afer)
The cousisuove carves dtm othe Inver ll Fig. 2 rave r=
voter Heil Sthe pore clostile ant WET — 1B for vw exalive,
‘whore Mi the total eoergy aor clone repceteated by the Forsontl net
tthe tp of the Sigur sl fe the atcha of Ue energy ing fn Te
Inesive eounal 8 ae 1). The every Ty The poise ta the
Tegaive ectrte by conduction ser elonure clearly for = «cP. Tae
lanipetsture fereace etwee te wires nau Ce ink eal (ZR
Gay 1) ana fiom analogy si he clr Fone Tar the apeating
rsistune of» circle eantet of ameter) the best dow fom one eee
tro © che other er secre ie found by melipying this tenperatore
‘erence by Ste ant the hes How er lose by Fatt viding by
iquatng Ue eae orb eo dines = {6 Bi 80)?
(BF att, Trecurven craven in Fig eave shane determined by this
apres wc the ben purameene al chosen to tthe expen
Pits. The vaulting values uf eal Pere: eg = O88)! = TEX IIPtem
Tor the inactive cles atl eg = O85, 48 3 I or the ato
Tithe ae af coma ene Ir cil and the rontactig electrode
seem craters nf pert! svt, bese values off be
sShruy late by sath theary the fvres hang the clecrreder
fag heer ny ane it nl. Pe reat = RO — See
where i the iter of theses, ie Vong’ neds > peta
set wie Vober rat. 1 tak f= 18% WP er the aha we
{Soyresal sagen vey os. Sam Dl gran wight No ign
ru say af econ alata cae vas frye als Ta le
Serve tx they see nor wlely unreassaale.
The averse pee of ime between the end of ech 2x¢ and contact of

2,
64) muy ur. even meeucaL UNA, OezomER 1951

Ue etnies at o¢ rane the olce where the ae coca em healt
Ios the velocity oft ravingeesde st coats: are Ur average sep
resin of the slectoibs bou “ie ae tee ple, Meerannts of
‘riaresioa heve born mute euler? Row caletleion a hla! tence
Tunes of ac eee hes th oso sae, ang eof es everage
lowat tine, brve shor hat ‘le wostect fede ther le temp
Toma act atl for shove the mean esses a the ele of the tee
(Govhaps higher I 10°C), The lca teaperatces rl the wap ter
peratures in tine wii’ vey soz i cmpeioey wth 1/69 secon
ne thus tae cordon ol ext va ths poste so the ogee elie
Shen this nal i tempore ref nae ere fo by te estrarettinrs
Sf he curve Lig. 2Tai conection ean He au obtaining AP meas
‘rements or deten lected relociuanéenteiting on velocity
‘Soe lata ae ote in Fig. 8. isu ine Chat the ce fe bee
af wi fghse masz bese horizon’ sa ey appnonch reo vali,
That tw ee “heorsies! seein has buen made gunn thee shapes
“The cderenes ramen Fie? vols atthe woos of Pe tata of Vis 2
ane et a2 veloc y ae the rca sovectiors, an hese age rien
on on Foe 2 af Table 1, The corseetion sere ile sna (001°C),
Sr pshays men, fo Ue astveelsetredes (Fgh Parle of Fig, bu
mounting Inaboat | LMI? or the iacctve electrodes (eth ie.
ha the cra 0a besa: tint tbr ie wih eur kr
‘edge tna so a iat elestedce wich an appa ig eae ther
ecur whos ne faite apart ta eecendes ce active than i Sey

he ves of ATy after plying He sanectons of ine of Table Te
seit isi on in vee given ale (cola; weasted values
GET for rae fe ovr a chet eonsnning an haere of 10
SOC aieh ormoletey prevented ay arcing £0 line Hace values ofthe
nergy diesjuted upon the cectogee pee elie cakulted Eom the 2
els of ie Cr sete eonsidercorernes Aue radiation 2-6 v1
{retion loves rm the sues of ee mined rao ss fom tea
Feels Tce len up oe 2 9tie inthe leg pasgesphs

TH hewn eeetina ars de to dln fro Te suslaces af he Yn
swine he bea pat che ene of wwe per ste e wos hereto
AT by tae equation

wen daa | HAMTYS, a
shave & ie thermal eurbetviy, a Land are espertivaly the ere.
Testi ave, length and sutlice ata of the wine, ate J Finn, oe
vo mustosntos At stsentones of anon? nenertic ane OTT

stot suilistioa” Far Ty ~ 300°R aod Lie emily «— O08 at
too temperate te second te of hs expsion rue rete
loure e the values ated “aati tne” an Te $ of Tae
thew coetons are negli

"Te coven ie an 8 hovkontal eye of dete D hs ae
sven a8 O27ACQTPYD" Ia BIT. shone wba ineF, Daft and
Ai gue et Fr usar of una Uns comes LIBUA(ATP/ Do
Gegpae. To maith dere‘ wjaton fr boa ne Hee Shs as be
tn sptocately 190A A7WB}"A7 a he at pt tote
fof he eo acon tang accu cavestin lone would thes be
fren by equation {1) wih 17 ~ SUG0(@7./2D}%. The second tena of thie
(preson reduces tocga pe lai as tie Aue lala “onerion
oteston on fing the tbl

“That the ath from Ue te efile eligible oka trom
totale ofthe dation of the are and of ite supertelalaea, The are
tie iw LC wach oe the vale OUT aad BA 310 ee epctialy
tor art fr the netics The sverege eh Ne A
‘ehh i elev fn aang inp a ele Than te en
{us pit el oa aoe the strlen. Te some experinenis
feos found thas — 38% 50 cnfeng Ichi aint op tsar
Insight forthe pst tata ed we la late femgeratre 1 Me Ie
Tesing poi of pin” $800 nod education othe ae 3100
he cog ee comer ot co Be OO ey Tea res epper Ea

ARenuestos or ae Dass,

[Not allat tne waery i the Chant cadens ic ates in an ate 09
lace Daring hea cna fell hy ener ang eh
‘ite eistanes,incoding sprescing vsctance inthe dactades st the ste
ofthe are, a afr the atc over al ofthe semainng euergy eso diss
pated, We need ta srt out the amounts of cueigy wich ave pon a these
tiles seg or fo mike care anys of the da represented
hy the muribecson ies Tan 8 of Table I

ye tte enerey ise, ~ CH/2 where — 10 *fead V,~ AO yalsinel
Cie enperimente af hi pape> fon 8 ergs "Te oengy lester ine
src free = Ci — Vij where Fy = —8 sts rhe potential acros the

TIL Gon ed. Jr, etn a Sa"

SEAR Gals ye wall and. See apc A.C. Worthing a
vest yr Be Mek Hest ‘estean” ce EO HS qetins Cand
Aen

Se ea AP Ph 8S US
912 uw wna, seamen aR OIoAr Joe, SstOBEH 19ST

ose clectroes wher. the are is vera! ~ 35 Gor phtnum isthe ave
voltage aeeomel bie ait cota darigthe is of ech wre whi
srry eons true, Pheenrgy eft tae cies after ana is ore eV /2.
he ll uty dite thee CHE? (Py — Ye FP
during the ate ps CV%/2 altereards, Wren elmure ascre withow: a
iv ttwditions 2) fhe otal nal energy CV/2 ie dispoted in te ci
i Some ofthe sicut energy spn the eectravte ites anism
ted, asthown by the numbers of Favs 7 ari of clara 2. tan probably
be safely espuntl Eat the rnin ofthe crcit energy whi appests i
the ered wares isthe sume whaler or not there face. Wit this
Semone and lose Ve wd. ye ean et the dat. of colons 2
fod 2 Uy ralelete Ovo parunety, nthe fection of Che cucu energy
hich appear in te lett te, nil the Faction of she ace energy
Ietich it liaiguted upon te aitive electrode for the acsive contin.
The dats of columns bare tobe wat wit Ubose of columns 2 and 3
caw of a diferent etrical zeit syd in mnsequence a ciferent Cant
so doubt erg) vali
‘Quai of intrest ae ds ee

Total enengy #5 — CV?

fre energy t= CU ~ Hy)

nen wih mews | a6, ge le — el

fire vals Tate, ys
factor hy whieh al enemy maasueneats aren
fertorfi., experimental aos} e

fraction of ar eneny a psitive lectrode &
values obtained [ar pute clot, sy
‘by mewansnen [ats negative elle,

[pare total eres,

From the way thee defn have been given Fe cleat th
wm tye

w+ wer ell

sey = ea ee = eh

at

‘These equations yield
Flas dee = Ge ence
sawailien Ftc — (eo aed
B= Phas — ee ab te
“The known murnsicl values of C Vo, Prana gee, inengs a — 90,6,
FS, det vvangy eesipeted daring an are — 11.25, cna energy dis

Raton Table pore Wt