natgillin/translations-raw huggingface dataset:
The temperature is measured on the outside wall of the vessel containing the sample or in the vessel itself.
Temperatura se meri ob zunanji steni posode z vzorcem ali v sami posodi.
Using the apparatus as described in figure 3a, fill the U-tube with the chosen liquid, which must be degassed at an elevated temperature before readings are taken.
S pomočjo aparature, kakor je prikazana na sliki 3a, se U-cevka napolni z izbrano tekočino, ki jo je treba pred odčitavanjem razpliniti pri zvišani temperaturi.
The test substance is placed in the apparatus and degassed at reduced temperature.
V aparaturo se da preskusna snov in razplini pri znižani temperaturi.
In the case of a multiple-component sample, the temperature should be low enough to ensure that the composition of the material is not altered.
Pri večkomponentnih vzorcih mora biti temperatura dovolj nizka, da se sestava snovi zagotovo ne spremeni.
Equilibrium can be established more quickly by stirring.
Vzpostavljanje ravnotežja je mogoče pospešiti z mešanjem.
The sample can be cooled with liquid nitrogen or dry ice, but care should be taken to avoid condensation of air or pump-fluid.
Vzorec se lahko ohladi s tekočim dušikom ali suhim ledom, paziti pa je treba, da zrak ali tekočina v črpalki ne kondenzira.
If necessary, the degassing operation is repeated several times.
Postopek razplinjevanja se po potrebi večkrat ponovi.
Test substance
1: Preskusna snov
Vapour phase
2: Parna faza
High vacuum valve
3: Visokovakuumski ventil
U-tube (auxiliary manometer)
4: U-cevka (pomožni manometer)
Pressure indicator
5: Indikator tlaka
Temperature bath
6: Temperaturna kopel
Temperature measuring device
7: Naprava za merjenje temperature
To vacuum pump
8: Vod do vakuumske črpalke
Ventilation/nitrogen
9: Zračenje/dušik
When the sample is heated with the valve closed, the vapour pressure increases.
Ko se vzorec segreva in je ventil zaprt, parni tlak narašča.
To compensate for this, nitrogen or air is admitted to the apparatus until the differential pressure indicator is at zero again.
Za izravnavo tega učinka se v aparaturo spusti dušik ali zrak, dokler ni indikator tlaka spet na ničli.
The pressure required for this can be read off the manometer or off an instrument of higher precision.
Tlak, potreben za to, se lahko odčita z manometra ali zelo preciznega instrumenta.
This pressure corresponds to the vapour pressure of the substance at the temperature of the measurement.
Ta tlak ustreza parnemu tlaku snovi pri tej merilni temperaturi.
Using the apparatus described in figure 3b, the vapour pressure is read off directly.
Pri uporabi aparature, prikazane na sliki 3b, se parni tlak odčita neposredno.
The vapour pressure is determined at suitably small temperature intervals (approximately 5 to 10 measuring points in all) up to the desired temperature maximum.
Parni tlak se določi pri ustrezno majhnih temperaturnih intervalih (skupaj približno 5 do 10 merilnih točk) do želenega maksimuma.
If the values obtained from the repeated readings do not coincide with the curve obtained for increasing temperature, this may be due to one of the following situations:
Če vrednosti, dobljene pri ponovljenih meritvah, ne sovpadajo z dobljeno krivuljo za naraščajočo temperaturo, je to lahko posledica enega od naslednjih vzrokov:
the sample still contains air (e.g. in the case of highly viscous materials) or low-boiling substances which is or are released during heating;
v vzorcu je še vedno zrak (npr. snovi z veliko viskoznostjo) ali snovi z nizkim vreliščem, ki se sprosti(-jo) med segrevanjem;
the substance undergoes a chemical reaction in the temperature range investigated (e.g. decomposition, polymerisation).
v proučevanem temperaturnem območju snov kemično reagira (npr. razpada, polimerizira).
Isoteniscope Method
Metoda izoteniskopa
The isoteniscope (6) is based on the principle of the static method.
Izoteniskop (6) temelji na principu statične metode.
The method involves placing a sample in a bulb maintained at constant temperature and connected to a manometer and a vacuum pump.
Ta metoda zajema namestitev vzorca v bučko, v kateri se ohranja konstantna temperatura in ki je povezana z manometrom ter vakuumsko črpalko.
Impurities more volatile than the substance are removed by degassing at reduced pressure.
Nečistoče, ki so bolj hlapne kot snov, se odstranijo z razplinjevanjem pri znižanem tlaku.
The vapour pressure of the sample at selected temperatures is balanced by a known pressure of inert gas.
Parni tlak vzorca pri izbranih temperaturah se uravnava z znanim tlakom inertnega plina.
The isoteniscope was developed to measure the vapour pressure of certain liquid hydrocarbons but it is appropriate for the investigation of solids as well.
Izoteniskop je bil razvit za merjenje parnega tlaka določenih tekočih ogljikovodikov, vendar ga je mogoče uporabiti tudi za proučevanje trdnih snovi.
The method is usually not suitable for multicomponent systems.
Ta metoda običajno ni primerna za večkomponentne sisteme.
Results are subject to only slight errors for samples containing non-volatile impurities.
Pri vzorcih, ki vsebujejo nehlapne nečistoče, lahko rezultati vsebujejo majhne napake.
The recommended range is 102 to 105 Pa.
Priporočeno območje je od 102 do 105 Pa.
An example of a measuring device is shown in figure 4.
Primer merilne naprave je prikazan na sliki 4.
A complete description can be found in ASTM D 2879-86 (6).
Popoln opis je mogoče najti v ASTM D 2879–86 (6).
In the case of liquids, the substance itself serves as the fluid in the differential manometer.
Pri tekočinah se sama snov uporabi kot tekočina v diferencialnem manometru.
A quantity of the liquid, sufficient to fill the bulb and the short leg of the manometer, is put in the isoteniscope.
V izoteniskop se vlije zadostna količina tekočine, da se napolnita bučka in krajši krak manometrskega dela.
The filled isoteniscope is placed in a horizontal position so that the sample spreads out into a thin layer in the sample bulb and manometer.
Napolnjen izoteniskop se postavi v vodoraven položaj, tako da se vzorec razlije v tanko plast v vzorčni bučki in manometrskem delu.
The pressure of the system is reduced to 133 Pa and the sample is gently warmed until it just boils (removal of dissolved gases).
Tlak v sistemu se zmanjša na 133 Pa in vzorec se počasi segreva, dokler ravno ne začne vreti (odstranitev raztopljenih plinov).
The isoteniscope is then placed so that the sample returns to the bulb and fills the short leg of the manometer.
Izoteniskop se nato postavi tako, da se vzorec vrne v bučko in krajši krak manometra ter se oba popolnoma napolnita s tekočino.
The pressure is maintained at 133 Pa.
Vzdržuje se tlak 133 Pa.
The drawn-out tip of the sample bulb is heated with a small flame until the sample vapour released expands sufficiently to displace part of the sample from the upper part of the bulb and manometer arm into the manometer, creating a vapour-filled, nitrogen-free space.
Podaljšana konica bučke z vzorcem se segreva nad majhnim plamenom, dokler se sproščene pare vzorca toliko ne razširijo, da izpodrinejo del vzorca iz zgornjega dela bučke in kraka manometra, ga potisnejo v manometrski del izoteniskopa, in tako ustvarijo s parami nasičen prostor brez dušika.
The isoteniscope is then placed in a constant temperature bath, and the pressure of the nitrogen is adjusted until it equals that of the sample.
Izoteniskop se nato postavi v kopel s konstantno temperaturo, tlak dušika pa se naravna tako, da je enak tlaku vzorca.
At the equilibrium, the pressure of the nitrogen equals the vapour pressure of the substance.
Ob ravnotežju je parni tlak dušika enak parnemu tlaku snovi.
Pressure control
A: Sistem za tlak
8 mm OD Tube
B: Cev z zunanjim premerom 8 mm
Dry nitrogen in pressure system
C: Suhi dušik v tlačnem sistemu
Sample vapour
D: Para vzorca
Small tip
E: Majhna konica
Liquid sample
F: Tekoči vzorec
(Dimension in mm)
(Mere v mm)
In the case of solids, and depending on the pressure and temperature ranges, manometer liquids such as silicon fluids or phthalates are used.
Pri trdnih snoveh se odvisno od območja tlaka in temperature uporabljajo manometrske tekočine, kot so silikonske tekočine ali ftalati.
The degassed manometer liquid is put in a bulge provided on the long arm of the isoteniscope.
Izboklina na daljšem kraku izoteniskopa se napolni z razplinjeno manometrsko tekočino.
Then the solid to be investigated is placed in the sample bulb and is degassed at an elevated temperature.
Potem se preskusna trdna snov da v bučko in razplini pri zvišani temperaturi.
After that, the isoteniscope is inclined so that the manometer liquid can flow into the U-tube.
Nato se izoteniskop nagne tako, da manometrska tekočina steče v U-cevko.
Effusion method: vapour pressure balance (7)
Efuzijska metoda: parnotlačna tehtnica (7)
A sample of the test substance is heated in a small furnace and placed in an evacuated bell jar.
Vzorec preskusne snovi se segreje v majhni peči in namesti v odzračen stekleni zvon.
The furnace is covered by a lid which carries small holes of known diameters.
Peč se pokrije s pokrovom, na katerem so majhne luknje z znanimi premeri.
The vapour of the substance, escaping through one of the holes, is directed onto a balance pan of a highly sensitive balance which is also enclosed in the evacuated bell jar.
Para snovi, ki uhaja skozi eno izmed lukenj, se usmeri v skodelico zelo natančne tehtnice, ki je tudi zaprta v odzračenem steklenem zvonu.
In some designs the balance pan is surrounded by a refrigeration box, providing heat dissipation to the outside by thermal conduction, and is cooled by radiation so that the escaping vapour condenses on it.
Pri nekaterih različicah je skodelica tehtnice obdana s hladilno posodo, ki zagotavlja odvajanje toplote navzven s termično prevodnostjo, in se ohlaja s sevanjem, zato da uhajajoča para kondenzira na njej.
The momentum of the vapour jet acts as a force on the balance.
Moment curka pare deluje kot sila na tehtnico.
The vapour pressure can be derived in two ways: directly from the force on the balance pan and also from the evaporation rate using the Hertz-Knudsen equation (2):
Tlak pare je mogoče izpeljati na dva načina: neposredno od sile na skodelico tehtnice, pa tudi iz hitrosti izparevanja s pomočjo Hertz-Knudsenove enačbe (2):
G evaporation rate (kg s–1 m–2)
G hitrost izhlapevanja (kg s–1 m–2)
M molar mass (g mol–1)
M molska masa (g mol–1)
R universal gas constant (J mol–1 K–1)
R splošna plinska konstanta (J mol–1 K–1)
P vapour pressure (Pa)
p parni tlak (Pa)
The recommended range is 10–3 to 1 Pa.
Priporočeno območje je od 10–3 do 1 Pa.
The general principle of the apparatus is illustrated in figure 5.
Glavni princip aparature je prikazan na sliki 5.
Base plate
Osnovna plošča
Refrigeration box and cooling bar
Hladilna posoda in hladilna palica
Moving coil instrument
Inštrument z vrtljivo tuljavo
Evaporator furnace
Uparjalna peč
Bell jar
Stekleni zvon
Dewar flask with liquid nitrogen
Dewarjeva posoda s tekočim dušikom
Balance with scale pan
Tehtnica s skodelico
Vacuum measuring device
Naprava za merjenje vakuuma
Test Substance
Preskusna snov
The method is based on the estimation of the mass of test substance flowing out per unit of time of a Knudsen cell (8) in the form of vapour, through a micro-orifice under ultra-vacuum conditions.
Ta metoda temelji na oceni mase preskusne snovi, ki v obliki pare zapusti Knudsenovo celico (8) v časovni enoti skozi mikroodprtino v pogojih ultra visokega vakuuma.
The mass of effused vapour can be obtained either by determining the loss of mass of the cell or by condensing the vapour at low temperature and determining the amount of volatilised substance using chromatography.
Masa izhajajoče pare se lahko ugotovi tako, da se bodisi določi izguba mase celice bodisi kondenzira para pri nizki temperaturi in določi količina izhlapele snovi s kromatografsko analizo.
The vapour pressure is calculated by applying the Hertz-Knudsen relation (see section 1.5.4.1) with correction factors that depend on parameters of the apparatus (9).
Parni tlak se izračuna z uporabo Hertz-Knudsenovega razmerja (glej točko 1.5.4.1) s korekcijskimi faktorji, ki so odvisni od parametrov aparature (9).
The recommended range is 10–10 to 1 Pa (10)(11)(12)(13)(14).
Priporočeno območje je 10–10 to 1 Pa (10)(11)(12)(13)(14).
The general principle of the apparatus is illustrated in figure 6.
Glavni princip aparature je prikazan na sliki 6.
Connection to vacuum
Povezava z vakuumom
Threaded lid
Navojni pokrov
Wells from platinum resistance thermometer or temperature measurement and control
Luknje v platinskem uporovnem termometru ali sistemi za merjenje in nadzorovanje temperature
Butterfly nuts
Krilne matice
Lid for vacuum tank
Pokrov vakuumske posode
Bolts
Vijaki
O-ring
O-tesnilo
Stainless steel effusion cells
Efuzijske celice iz nerjavečega jekla
Aluminum vacuum tank
Aluminijasta vakuumska posoda
Heater cartridge
Grelni vložki
Device for installing and removing the effusion cells
Naprava za pritrjevanje in odstranjevanje efuzijskih celic
The method is based on the determination of accelerated evaporation rates for the test substance at elevated temperatures and ambient pressure using thermogravimetry (10)(15)(16)(17)(18)(19)(20).
Ta metoda temelji na določitvi pospešenih hitrosti izhlapevanja preskusne snovi pri povišanih temperaturah in zračnem tlaku s postopkom termogravimetrije (10)(15)(16)(17)(18)(19)(20).
The evaporation rates vT result from exposing the selected compound to a slowly flowing inert gas atmosphere, and monitoring the weight loss at defined isothermal temperatures T in Kelvin over appropriate periods of time.
Hitrosti izhlapevanja vT nastanejo pri izpostavljanju izbrane snovi počasi tekoči atmosferi inertnega plina in spremljanju izgube teže pri opredeljenih izotermičnih temperaturah T v kelvinih v ustreznih časovnih obdobjih.
The vapour pressures pT are calculated from the vT values by using the linear relationship between the logarithm of the vapour pressure and the logarithm of the evaporation rate.
Parni tlaki pT se izračunajo iz vrednosti vT na podlagi linearnega razmerja med logaritmom parnega tlaka in logaritmom hitrosti izhlapevanja.
If necessary, an extrapolation to temperatures of 20 and 25 °C can be made by regression analysis of log pT vs. 1/T.
Po potrebi se izvede ekstrapolacija na temperaturi 20 in 25 °C s pomočjo regresijske analize log pT v odvisnosti od 1/T.
This method is suitable for substances with vapour pressures as low as 10–10 Pa (10–12 mbar) and with purity as close as possible to 100 % to avoid the misinterpretation of measured weight losses.
Ta metoda je primerna za snovi s parnimi tlaki do 10–10 Pa (10–12 mbar) in s čistostjo, ki je kar najbližje 100 %, da ne pride do napačne razlage izmerjenih izgub teže.
The general principle of the experimental set-up is shown in figure 7.
Glavni princip postavitve preskusa je prikazan na sliki 7.
After leaving the chamber, the gas stream is purified by a sorption unit.
Ko plinski tok zapusti komoro, se očisti v napravi za sorpcijo.
The test substance is applied to the surface of a roughened glass plate as a homogeneous layer.
Preskusna snov se nanese na površino hrapave steklene plošče v enakomerni plasti.
In the case of solids, the plate is wetted uniformly by a solution of the substance in a suitable solvent and dried in an inert atmosphere.
Pri trdnih snoveh se plošča enakomerno zmoči z raztopino snovi v ustreznem topilu in posuši v inertni atmosferi.
For the measurement, the coated plate is hung into the thermogravimetric analyser and subsequently its weight loss is measured continuously as a function of time.
Za izvedbo meritev se prevlečena plošča obesi v termogravimetrični analizator, nato pa se izguba teže neprekinjeno meri kot funkcija časa.
The evaporation rate vT at a definite temperature is calculated from the weight loss Δm of the sample plate by
Hitrost izparevanja vT pri dani temperaturi se izračuna iz zmanjšanja mase Δm plošče z vzorcem s pomočjo naslednje enačbe:
where F is the surface area of the coated test substances, normally the surface area of the sample plate, and t is the time for weight loss Δm.
kjer je F površina prevlečenih preskusnih snovi, običajno površina plošče z vzorcem, t pa je čas, v katerem se je masa zmanjšala za Δm.
The vapour pressure pT is calculated on the basis of its function of evaporation rate vT:
Parni tlak pT se izračuna na podlagi njegove funkcije hitrosti izparevanja vT:
where C and D are constants specific for the experimental arrangement used, depending on the diameter of the measurement chamber and on the gas flow rate.
kjer sta C in D konstanti, specifični za uporabljeno preskusno postavitev in odvisni od premera merilne komore ter hitrosti pretoka plina.
These constants must be determined once by measuring a set of compounds with known vapour pressure and regressing log pT vs. log vT (11)(21)(22).
Ti konstanti se določita enkrat, in sicer z merjenjem nabora snovi z znanimi parnimi tlaki in regresijo log pT v odvisnosti od log vT (11)(21)(22).
The relationship between the vapour pressure pT and the temperature T in Kelvin is given by
Razmerje med parnim tlakom pT in temperaturo T v kelvinih je podano z
where A and B are constants obtained by regressing log pT vs. 1/T.
kjer sta A in B konstanti, pridobljeni z regresijo log pT v odvisnosti od 1/T.
With this equation, the vapour pressure can be calculated for any other temperature by extrapolation.
S to enačbo je mogoče z interpolacijo izračunati parni tlak za katero koli drugo temperaturo.
Gas saturation method (23)
Metoda z nasičenjem plina (23)
Inert gas is passed, at room temperature and at a known flow rate, through or over a sample of the test substance, slowly enough to ensure saturation.
Inertni plin se pri sobni temperaturi in pri znanem pretoku spelje skozi oziroma čez vzorec preskusne snovi, in sicer dovolj počasi, da se zagotovi nasičenje.
Achieving saturation in the gas phase is of critical importance.
Ključnega pomena je, da v plinski fazi nastopi nasičenje.
The transported substance is trapped, generally using a sorbent, and its amount is determined.
Prenesena snov se ujame, običajno s pomočjo sorbenta, nato se določi njena količina.
As an alternative to vapour trapping and subsequent analysis, in-train analytical techniques, like gas chromatography, may be used to determine quantitatively the amount of material transported.
Za določitev količine snovi, ki jo prenese znana količina nosilnega plina, se namesto lovljenja pare in poznejše analize lahko uporabijo neposredne analitske tehnike, kot je kromatografija.
The vapour pressure is calculated on the assumption that the ideal gas law is obeyed and that the total pressure of a mixture of gases is equal to the sum of the pressures of the component gases.
Parni tlak se izračuna ob predpostavki, da se upošteva zakon idealnega plina in da je skupni tlak mešanice plinov enak vsoti tlakov posameznih plinov.
The partial pressure of the test substance, i.e. the vapour pressure, is calculated from the known total gas volume and from the weight of the material transported.
Delni tlak preskusne snovi, tj. parni tlak, se izračuna iz znane skupne prostornine plina in iz teže prenesenega materiala.
The gas saturation procedure is applicable to solid or liquid substances.
Postopek z nasičenjem plina se lahko uporablja za trdne ali tekoče snovi.
It can be used for vapour pressures down to 10–10 Pa (10)(11)(12)(13)(14).
Uporabiti ga je mogoče za parne tlake do 10–10 Pa (10)(11)(12)(13)(14).
The method is most reliable for vapour pressures below 103 Pa.
Metoda je najzanesljivejša za parne tlake, nižje od 103 Pa.
Above 103 Pa, the vapour pressures are generally overestimated, probably due to aerosol formation.
Pri tlakih nad 103 Pa so parni tlaki običajno precenjeni, najverjetneje zato, ker se tvorijo aerosoli.
Since the vapour pressure measurements are made at room temperature, the need to extrapolate data from high temperatures is not necessary and high temperature extrapolation, which can often cause serious errors, is avoided.
Ker se meritve parnega tlaka izvajajo pri sobni temperaturi, ni potrebe za ekstrapolacijo podatkov iz visokih temperatur, zato se ekstrapolacija pri visokih temperaturah, ki pogosto povzroča resne napake, ne izvaja.
The procedure requires the use of a constant-temperature box.
Ta postopek zahteva uporabo posode s konstantno temperaturo.
The sketch in figure 8 shows a box containing three solid and three liquid sample holders, which allow for the triplicate analysis of either a solid or a liquid sample.
Na skici na sliki 8 je prikazana posoda s tremi pripravami za trdne in tremi pripravami za tekoče vzorce, ki omogočajo trojno analizo trdnega ali tekočega vzorca.
The temperature is controlled to ±0,5 °C or better.
Natančnost nadzora temperature je na ±0,5 °C ali boljša.
In general, nitrogen is used as an inert carrier gas but, occasionally, another gas may be required (24).
Običajno se za inertni nosilni plin uporablja dušik, občasno pa je treba uporabiti tudi kak drug plin (24).
The carrier gas must be dry.
Nosilni plin mora biti suh.
The gas stream is split into 6 streams, controlled by needle valves (approximately 0,79 mm orifice), and flows into the box via 3,8 mm i.d. copper tubing.
Tok plina se razdeli na 6 tokov, ki jih nadzirajo igelni ventili (z odprtino približno 0,79 mm), in teče v posodo po 3,8 mm i.d. bakreni cevi.
After temperature equilibration, the gas flows through the sample and the sorbent trap and exists from the box.
Po izenačitvi temperature plin teče skozi vzorec in sorbentno past, nato pa zapusti posodo.
Solid samples are loaded into 5 mm i.d. glass tubing between glass wool plugs (see Figure 9).
Trdni vzorci se namestijo v 5 mm i.d. stekleno cev med čepe iz steklene volne (glej sliko 9).
Figure 10 shows a liquid sample holder and sorbent system.
Na sliki 10 sta prikazana naprava za tekoče vzorce in sorbentni sistem.
The most reproducible method for measuring the vapour pressure of liquids is to coat the liquid on glass beads or on an inert sorbent such as silica, and to pack the holder with these beads.
Najbolj ponovljiva metoda za merjenje parnega tlaka tekočin je, da se tekočina nanese na steklene kroglice ali na inerten sorbent, kot je na primer silicijev oksid, nato pa se naprava napolni s temi kroglicami.
As an alternative, the carrier gas may be made to pass a coarse frit and bubble through a column of the liquid test substance.
Alternativno se lahko nosilni plin spelje mimo hrapavega frita in v obliki mehurčkov skozi steber tekoče preskusne snovi.
At very low vapour pressures, only small amounts are retained by the sorbent and the adsorption on the glass wool and the glass tubing between the sample and the sorbent may be a serious problem.
Pri zelo nizkih parnih tlakih sorbent zadrži le majhne količine, zato lahko adsorpcija na stekleni volni in steklenih ceveh med vzorcem in sorbentom povzroča velike težave.
Traps cooled with solid CO2 are another efficient way for collecting the vaporised material.
Pasti, ohlajene s trdnim CO2, so še en učinkovit način za zbiranje uparjenega materiala.
They do not cause any back pressure on the saturator column and it is also easy to quantitatively remove the trapped material.
Ne povzročajo protitlaka na saturacijsko kolono, prav tako pa je mogoče zelo enostavno kvantitativno odstraniti ujeti material.
The flow rate of the effluent carrier gas is measured at room temperature.
Pretok iztočnega nosilnega plina se meri pri sobni temperaturi.
The flow rate is checked frequently during the experiment to assure that there is an accurate value for the total volume of carrier gas.
Pretok se med preskusom pogosto preverja, da se zagotovi pravilna vrednost za skupno prostornino nosilnega plina.
Continuous monitoring with a mass flow-meter is preferred.
Zaželeno je spremljanje ves čas z merilnikom masnega pretoka.
Saturation of the gas phase may require considerable contact time and hence quite low gas flow rates (25).
Nasičenje plinske faze lahko zahteva dolg čas stika in zato precej nizke hitrosti pretoka plina (25).
At the end of the experiment, both the front and backup sorbent sections are analysed separately.
Ob koncu poskusa se sprednji in pomožni sorbentni del analizirata ločeno.