AIR DENSIY AND IS UNCERAINY Mnel Slzr Mri Veg
CONENS Air nd is comosiion Wys o clcle e ir densiy Cr CIPM Eqion Aroxime eqion Unceriny
Air nd is comosiion e ir is mixre of seerl gses dry ir, nd wer in sem form. roosere is e inferior lyer of e erresril mosere, erresril srfce lide of 6 o 8 kilomeers, e ir we breed is concenred ere. e dry ir s e wer sem bees like idel gses. ey e been deeloed o emiricl lws rele e mcroscoic les, in idel gses, ese les inclde ressre (), olme (V) nd emerre () Ley de Crles Ley de Gy-Lssc Ley de Boyle IDEAL GAS LAW
Air nd is comosiion I is consied by nirogen mixre nd of oxygen like bsic elemen (99%) nd e res like noble gses. e comosiion is similr rond e world. Wer Sem (0-5%), Crbon dioxide, ydrocrbons, rs, ses, ds nd SO. Elemeno Nirógeno Oxigeno Argón Neón Helio Crión COMPOSICION DEL AIRE PURO Proorción en olmen 78,4 0,9,5 0-3 5 0-4 0-4 0,7 0-4 Elecricl deliery form CH, H0, 03, NO3H, NH3, Hidrogeno 5 0-5 NO3NH4. enón 0-5 4 0 0,94 Proorción en eso 75,6 3, 0,3 0-3 3 0-4 0,35 0-5 4 0-5
Wys o clcle e ir densiy Densiy defined in qliie mnner s e mesre of e relie mss of objecs wi consn olme Hyoesis de Aogdro wo gses sme olme (sme ressre nd emerre) conin e sme nmber of ricles, or molecles Sndrd Lw gses P.V n. R. n m/mr
Wys o clcle e ir densiy As fncion of lide Using refrcomeer Air boyncy refcs meods Eqion CIPM /8 Aroxime eqion
Wys o clcle e ir densiy AS FUNCION OF ALIUDE Amoseric ressre dros bo or bo. mbr (kp( kp) for ec 00 meers. Densiy decreses
Wys o clcle e ir densiy AS FUNCION OF ALIUDE L 6,5 emerre lse re, deg K/km H geooencil lide geomericl lide o emerre ºK Po Amoseric Pressre
Wys o clcle e ir densiy REFRACROMERY Cnges in ir densiy cn be deermined wi good recision sing n oicl meod bsed on e ig correlion beween ir densiy nd ir index of refrcion. R secific refrcion or e refrcionl inrin in ncion comosiion of ir nd e locl moseric condiions n is deermined by simle rio of lser freqencies: n ν ν cio ire ν cio lser freqency locked o one rnsmission ek of e inerferomeer nder cm ν ire e freqency locked o e sme ek of e inerferomeer lced in ir.
Wys o clcle e ir densiy AIR BUOYANCY AREFACS MEHODS e meod is bsed on e weiging of wo refcs ing e sme nominl mss nd e sme srfce re b wi ery differen olmes. wo weigings re necessry o deermine e ir densiy, one in ir nd one in cm m ire I I ( V V ) m m I e I blnce redings in ir mss V m e V m olme of m y m ir densiy m cío nd mss I 3 I 4 I 3 e I 4 e blnce redings in cm mss y mss m m σ S ire S S e difference in srfce re beween e wo refcs nd σ mss of dsorion er ni re. I cio 3 I 4 ( I I σ S) V m V m
Wys o clcle e ir densiy FORMULA CIPM From e eqion of se of non-idel gs nd e exerimenl condiions e densiy of mois ir Were M x 3 [,9635,0( x 0,0004) ]*0 8 co kgmol f (, ) s ( ) P ressre ermodynmic emerre 73,5 M molr mss of e wer comressibiliy fcor R molr gses consn
Wys o clcle e ir densiy APPROIMAE EQUAION From BIPM forml we obin one nmericl roxime eqion : 0,34848* 0,00904* 73,5 r * e 0,06*
Wys o clcle e Wys o clcle e ir densiy ir densiy PSYCHROMERY ermodynmic roeries of mixres of gs wi or.. srion ressre nd emerre of dew, Indexes of midiy, Volme, e nd mid enly, emerre of srion dibic nd we ermomeer. Some definiions: Relie Hmidiy. e relie midiy is e ercen of srion midiy,, generlly clcled in relion o sred or densiy, in (%): HR 00 P/Ps (%) emerre of dibic srion,, is e idel emerre of eqilibrim will e e ir non sred fer ndergoing n dibic nd isobric rocess (iso( enlic), i kes i emerre o e srion by mens of liqid eorion of wer o is. emerre of we ermomeer is e emerre i reces ermomeer coered wi we clo is exosed o n irflow wio sring i flows seeds ner 5 m/s Dew oin is e emerre, wic e moisre conen in e ir will sre e ir, If e ir is cooled frer, some of e moisre will condense.
Wys o clcle e ir densiy o mesre e midiy : PSYCHROMERY AREFAC MEHOD sycromeer ermodynmic ygromeer of ir or oers merils Hygromeer of dew oin Hygromeer of Cemis bsorion Hygromeer digil Hygroscoic Condension Grimeric Vriion of elecricl roeries
Wys o clcle e ir densiy PSYCHROMERY Psycromeer nd siro sycromeer Consis wo ermomeers, one norml (dry) nd noer wi eir blb ermnenly midified nks o clo or we gze i recoers i. e midiy cn be mesred beween bo sring from e difference of emerre rses
Wys o clcle e ir densiy Digrm Crrier. - e reresens (ºC) in e bsciss xis (xis x) nd e mixre reson or midiy (, in kg of wer/kg of dry ir) in e xis of orderly (xis nd, o e rig). - e srion cre (HR 00%) i scends owrd e rig nd i reresens e end of e digrm. In is cre e emerres of mid ermomeer nd e emerres of dew re loced. - - e cres of midiy relie consn re similr o of srion, dncing down (lying down more) s i diminises e midiy of e ir. PSYCHROMERY
Wys o clcle e ir densiy CHAR 0.8.8 0.79 0.78 ( 9, 40 %, ) 0.77 ( 0, 40 %, ) 0.76 0.75 (, 40 %, ) 0.74 ( 4, 40 %, ) 0.73 0.7 0.7 0.7 0.7 600 60 60 630 640 650 660 670 680 690 700 600 700...6. ( 9, 50%, ).08 ( 0, 50%, ).04 (, 50%, ) 0.96 ( 4, 50%, ) 0.9 0.88 0.84 0.8 0.8 660 694 78 76 796 830 864 898 93 966 000 660 000 Air densiy eled wi Relie midiy 40 %, emerre 9 ºC 4 ºC, ressre 600 mbr 700 mbr Air densiy wi eled wi Relie midiy 50 %, emerre 9 ºC 4 ºC, ressre 660 mbr 000 mbr
Wys o clcle e ir densiy..85.5 ( ) (,, 800) (,, 700) (,, 600) 0, r, 000 0 r 0 r 0 r..05 0.95 0.9 0.85 0.8 Air densiy eled wi CHAR 0.75 0.7 0.7 40 4 44 46 48 50 5 54 56 58 60 40 r Relie midiy 40 % - 60 %, emerre 0 ºC, ressre 600 mbr 000 mbr 60
Wys o clcle e ir densiy CHAR Air densiy eled wi Relie midiy 40 %,..89.7.4. (, 40, 000).08.05 (, 40, 800).0 0.99 0.96 0.93 0.99 0.9 9 9.6 0. 0.8.4.6 3. 3.8 4.4 5 emerre 9 ºC 5 ºC, 9 ressre 800 mbr 000 mbr 5
CALCULAION OF HE AIR DENSIY CIPM M R x M M Were: M R M Pressre of ir in P. molr mss of dry ir. Comressibiliy fcor Uniersl consn of idel gses emerre of ir in K molr frcion of wer sem molr mss of wer
Molr mss of dry ir, M If i considers consn of ir comonen M 0,08963 5440 kg mol - If i cn mesre e concenrion of CO M [8,9635,0 (( CO. - 0,0004)]* 0-3 kg mol -
Comressibiliy fcor, [ ( ) ( ) ] b b x c c x ( d ex ) 0 0 0 Were: Air ressre in P Air emerre in K Enironmenl emerre in o C 0, 58 3 0-6 K P - -,933 x 0-8 P -,043 x 0-0 K - P - b 0 5,707 x 0-6 K P - b -,05 0-8 P - C 0.9898 x 0-4 K P - C -,376 x 0-6 P - d,83 x 0-K K P - e -0,765 x 0-8 K P -
Uniersl Consn of idel gses, R R 8.3450 ± 8,4 x lo-6 6 J. mol -. K - Molr s frcion of wer sem, In fncion of relie midiy, x f (, ) s ( ) In fncion of emerre of dew oin, r s Were: s f, ) ( r f (, r ( Relie midiy Pressre of sred sem Fgciy fcor ) s r )
Enncemen fcor f f(, r ) f α β γ Were: α β γ,000 6 3.4 x 0-8 P - 5,6 x 0-7 K - Air ressre in P Air emerre in O C or dew oin emerre ( r ) in O C
Pressre of sred sem, s Px ex A s B C D Were: A,37 884 7 x 0-5 K- B -,9 3 6 x 0- K- C 33,937 0 47 D -6,343 64 5 x 03 K Air emerre in K or dew oin emerre (r) in K
UNCERAINY OF AIR DENSIY SOURCES OF UNCERAINY Amoseric emerre Clibrion of bromeric Resolion of bromeric Vriion of moseric ressre dring clibrion 3 3 U k d B B 4
Enironmenl condiions 3 Clibrion of ermomeer U k Resolion of insrmen d Vriion of emerre dring clibrion 3 4
Relie midiy of ir 3 Clibrion of ygromeer U k Resolion of ygromeer d Vriion of e ir relie midiy dring clibrion 3 4
Consn R of idel gses R 84x 0-7 J mol - K - Eqion djsmen for e deerminion of ir densiy ec 4 5 (x0 )(0,9495) 9,50x0 kgm 3
Sensiiiy Coefficien Pressre emerre Relie midiy. f f f f c P P f f P P f f c s s s s C
Were: ex D B A D C B A P s 8 0 3,4 P x f β f γ fp s P f x s
fp x s f P s ( ) [ ] ( ) 0 0 0 ) ( ex d C C b b ( ) ( ) [ ] ( ) 3 0 0 ex d C C b b o ( ) c b ( ) 0 e x c x c b b o
Consn R M M R M M M x R M M M R M M M R M M M R M R R C R molk j kgm CR 3 0,40368
Eqion Unceriny elion Degrees of freedom Exnded nceriny C ec ( ) [ ] i i x c ec ec R R n x ef 4 4 4 4 4 4 4 4 γ k U
: Were : ( ) ( ) ( )( ) ()( ) s s n n r n k k k, ( ) ( ) ( )( ) ()() s s n n r n k k k, ( ) ( ) ( )( ) ( ) () s s n n r n k k k, ( ) ( ) ( ) ( ) ( ) ( ), N i N i j j i j i j i i i i x x r x x c c x c Consider e moseric ressre, emerre nd relie midiy re correled, is nceriny:
Reference Esimciòn de l inceridmbre en l deerminciòn de l densidd del ire, Lis Omr Becerr Snigo y mrì Elen Grddo gonzàlez,, CENAM, Abril 003. Eqion for e deerminion of e densiy of Moir Air, R.S. Dis, Merologi 99,9,67-70. 70. Eqion for e deriminion of e densiy of mois ir,, P. gicomo.merologi 8,33-40 98. ree meods of deermining e densiy of mois ir dring mss comrisons,, A. Picrd y. Fng. Merologi 00, 39, 3-40. Discrencies in ir densiy deerminion beween e ermodynmic forml nd grimeric meod: eidence for new le of e mole frcion of rgon in ir,, A Picrd, H. Fng, Merologi 4, 396-400
nks for e enion